Home » IMAT Past Papers » IMAT Past Paper 2015 – Worked Solutions


1. B

Watch the lesson on assessing the impact of additional evidence

The passage is saying that fire (not temperature alone) is to blame for the lack of carbon on Earth, and that since there is fewer oxygen atoms further from the sun there is more carbon further from the sun. If the abundance of carbon increases the further away you get from the sun, this strengthens the argument. This is the case in option B

2. D

The cheapest price (standard) card that Tom can obtain with the correct measurement will cost him €1.50, while the cheapest deluxe is €1.95. 

He needs 50, so it will cost him either €75 for the standard or €97.5 for the deluxe cards, meaning the extra would come to €22.50.

3. D

Watch the lesson on identifying conclusions.

Here the last sentence is the conclusion, you can tell because it is the strongest opinion the author has and is what they are trying to convince us of. The word “would” is also a conclusion indicator word you should have noticed.

4. C

Calculate the area we will need to paint.

Ceiling: 4 x 6 =24m2

Long walls: 2 x 6 x 3.5 = 42m2

Short walls: 2 x 4 x 3.5 = 28m2

Window (will not be painted): 3m2

The total area to be painted is 91m2 but 18.2m2 will need a second coat, so we need to pain 109.2m2. One can will be able to paint 24m2, so a minimum of 5 cans will be needed.

5. E

The last sentence is the conclusion. If it is true that the students have not gained an interest in gardening then there is no point spreading the activity to other schools, so the correct answer is E

6. E

This is a distance over time graph, so the gradient shows the speed. 

Leroy is slower to start with and then speeds up halfway, so we should expect to see the gradient increase. This rules out all options except B and E. It cannot be B however since we are told that halfway he starts to increase speed, and in B it shows the increase earlier than that. So the answer is E

7. C

The conclusion is “Even so, fluoridation should not take place”. This rests on the fact that a campaign leader who lived in an area of fluoridation experienced negative side effects. The assumption linking this fact and the conclusion is therefore that fluoridation caused these negative effects. This matches option C.

8. B

For reasoning questions you need to brake the passage down into simple form. In this particular question there is only a certain portion that needs to be broken down, since the rest is just facts. The second and third sentence contain the reasoning. The reasoning can basically be boiled down to…

If we are concerned about A (in this case chemicals) we should not wait until we have B (in this case research) before we take action on A. 

If we look at option B it follows the exact same principle, that is if we are concerned about A (terrorists) we should not wait for B (in this case evidence) until we take action on A. 

9. D

1 and 2 must be the third and fifth numbers respectively, if we are to make the sum of the first three two-digit odd numbers less than 100. The first two numbers will then form 43.

We know neither the fourth or sixth numbers can be a 7, as a 7 and 3 would sum to 10, meaning the other odd number would have to be repeated in the final two digits. This means the last digit must be a 7 and the sequence is 4 3 1 5 2 9 8 7. 

10. A

The conclusions is “However, comparable studies elsewhere show that their fears are unfounded” which rests upon the facts that the great tits could adapt to climate change better than expected. This assumes that the other animals will be able to adapt in a comparable way to the great tits, which matches option A. You can also perform the negation technique (see the lesson on assumptions) to make sure that option A is the correct answer. 

11. E

First estimate the ratio for the cat, this should just be a rough estimate as you do not have a calculator. This is roughly 0.0015

Then calculate the ratio for all the animals listed (roughly). For the mouse it is 0.0016, for the pigeon it is 0.00008, for the squirrel it is 0.0043, for the rabbit it is 0.0011 and for the dog this is 0.0017

As seen the mouse has the closest ratio to the cat.

12. D

The passage has mentioned that the only two reasons to play sport are either for physical exercise or competition, and then goes on to say that pool does not involve physical exercise. A logical conclusion to this passage is thus that pool is played for competition which matches option D.

13. D

Draw out the numbers as they would be seen upside down (in the IMAT you can rotate the paper to see how this would look). Then reverse the order (since it was seen through the rear view mirror).

14. E

The conclusion is the strongest opinion of the author, that is what they are trying to convince the reader to believe/do. In this case the conclusion is “such an increase would  not be a good thing”. This corresponds to answer E.

15. A

The principle here can roughly be described as “something that is beneficial only to some people should not be forced on everyone”. Option A exhibits this same principle. 

16. A

The fast hovercraft will have gone for 1 hour and 10 minutes when it first starts leaving Genville. At this point the ferry has completed 1 hour and 10 minutes as well and still has to reach Genville which will take another 30 minutes. Draw a number line as seen below. From the slow ferries perspective there is 30 minutes left to travel until it reaches Genville. After 10 minutes it will be 10 minutes closer, but the hovercraft will have moved closer to the ferry. Since the hovercraft travels twice as fast as the ferry, the hovercraft will have covered the same distance in 10 minutes as the ferry would have in 20 minutes.

This means that the two will meet 10 minutes after the hovercraft leaves Genville, which is 1 hour and 20 minutes. 

17. A

By summing up all of the lengths between the poles we get 10.75m. If each rail is 2.4m long we need 4.48 rails, which means 5 in total will need to be used.

18. E

The principle in this passage is that while committing an act that may be done for the right reason and do good, it is not justified if it causes harm. This is exactly what is meant by the ends do not justify the means. 

19. D

She covers a total distance of 1,946 km, and she adds 140 litres of petrol of which 18 litres are filled on the last day, and are thus excluded. 

122 litres where thus used to travel 1,946 km. This means every 100 km, she uses roughly 6.3 litres. The option closest to this is option D. 

20. C

The question says there must be 1m of clear floor space around each of the tables it means they must fit into a 4m x 4m space. This rules out B and E. 

The tables are 1m wide and the display cases are only 0.2m wide, meaning that if we double them up longitudinally, we will get the best outcome. In C this arrangement is shown, 2 cases can fit on the left and right tables facing out. 1 facing in on each of the same tables can also be placed. Finally, one can fit facing down over the middle table and two can fit facing, making a total of 9

21. D

Max Weber was a famous sociologist and pedagogy is the study of teaching. If you knew this you would not need to know anything about the other scholars listed. 


Mahatma Gandhi was never awarded a Nobel Prize

23. C

LH and FSH both peak during ovulation. Just before ovulation, the concentration of progesterone rises and estrogen starts to fall.

24. D

The first that happens is that a signal is sent to muscle cells, meaning calcium ions are released by the Sarcoplasmic Reticulum. 

This then reveals the myosin binding sites on the actin, allowing the myosin heads to bind

The myosin heads will then release ADP and phosphate as they pull the actin

Myosin heads will then detach.

This order is given correctly by option D 

25. B

Lets list the different possible phenotypes (remember, a phenotype is a physical expression of the genes)

1. Rr or RR

2. rr

3. Qq or QQ

4. qq

There are thus 4 possible phenotypes

26. B

Below we will list the proportion of radioactive DNA to normal DNA as replication occurs

  1. 50:50
  2. 25:75
  3. 12.5:87.5

Thus there will be 87.5% normal DNA so this means row 1 must be correct. 

27. C

During water photolysis (splitting of water with light) we get oxygen and hydrogen ions (so protons). Water does not contain carbon, so carbon dioxide cannot be produced. The answer is thus C

28. A

A stem cell has the same number of chromosomes as a normal cell, so the gene will be present in one copy (meaning we will have two alleles, which in this case is Aa). At the start of mitosis DNA replication will already have occurred (in S phase) so we will have two gene copies (so AAaa). DNA replication also happens before meiosis 1 so we will also have AAaa in this case. This matches row 1.

29. B

When a sarcomere contracts the actin is pulled toward the myosin and this the area represented by 1 will get smaller. The actual actin filament itself does not compress however (it just moves inward) so 2 will not change.

30. C

All amino acids have a hydrogen, an amino group, a carboxyl group and then a variable (R) group (this is the group that varies between different amino acids). Clearly the methyl group (denoted as 2) must be the variable group. The carboxyl group is the acidic group and this is denoted as 3. This matches answer C

31. D

Osteocytes are found in the bone (the prefix osteo refers to bone). 

32. B

If the probe has complimentary DNA to the sequence it will fluoresce. 2 will bind to GATTAT and 3 will bind to TGGTCA. We can find both of these sequences in the main sequence so 2 and 3 are correct. 

33. E

X represents the earliest stage of a heart beat which is where blood leaves the atria to the ventricles. This means the volume of blood in the atria decreases. This also means the aortic valve must be closed so that blood doesn’t leave the ventricle while it is being filled up. The ventricle does not contract while it is being filled with blood so its muscles are relaxed. This matches row 1.

34. E

A normal eukaryotic cell will undergo mitosis, remember the abbreviation PMAT (prophase, metaphase, anaphase, telophase) and then what happens in each. 

Looking at row 3. Chromosomes line up at the equator (metaphase), spindle fibres shorten, pulling the chromosomes (anaphase), the nuclear envelope disappears (telophase), the cytoplasm divides (cytokinesis). These are all in the correct order.

35. A

Glucagon is a hormone, specifically a peptide hormone (so thus a protein). Make sure you read carefully, as the IMAT writers are tyring to trick you to think about glycogen or glucose with this question, so make sure that you read glucagon. 

36. C

A depolarisation occurs when positively charged sodium ions flow in, so if this anaesthetic makes the flow of sodium ions in more difficult, it will be harder to depolarise the neuron.

37. E

Descending order of size means things get smaller going rightwards. The nucleus is the largest, followed by the mitochondrion, followed by the ribosome. So the order is 2, 1, 3. 

38. C

Remember, transcription occurs wherever there is DNA. In a prokaryote there are no organelles, thus no mitochondria so we can rule out 2. Ribosomes have no DNA. In prokaryotes the DNA is located in the cytosol, so only 1 is correct

39. C

The mutated DNA sequence is ATCTTGCGG. That means after transcription we will get an mRNA sequence of UAG AAC GCC. Now the tRNA triplets that bind to these will be AUC UUG CGG. Following the table this will form the pattern seen in C.

40. D

Evolution can result in new species forming (speciation), it can also change the frequency of alleles and can result in an increase in biodiversity.

41. C

We are given the mass and the molar mass of carbon so we should first work out how many moles of carbon we have. Remember the formula M = m/n. 

For carbon: n = 0.6/12 = 0.05 moles. This means we also have 0.05 moles of the hydrocarbon, which means we can work out its molar mass. M = 0.75/0.05 = 15.

If the entire compounds molar mass is 15, and the molar mass of 1 carbon atom is 12, then we need 3 hydrogens (which each have a molar mass of 1) to get to 15 total molar mass of the compound. We thus know the compound has 3 hydrogens for each carbon, so the formula will be in the ratio CH3. Option C has this ratio

42. E

Remember M = m/n. For bromopropane M = 123. Therefore n = 0.2 for bromopropane. Looking at the formula we can see that the ratio of bromopropane to potassium hydroxide is 1:1, and bromopropane is the limiting reactant as we have excess KOH. That means 0.2 moles of bromopropane will react with 0.2 moles of KOH. This theoretically should yield 0.2 moles of propan1ol.

In reality we got 8g of propan­1­ol, which is 0.13 moles of propan­1­ol. Thus we take 0.13/0.2 x 100 = 66.7%.

43. D

The concentrations of H+(aq) and OH-(aq) will be the same as they are formed from just one reactant. 

Increasing the temperature will favour the right side of the reaction, creating more H+ ions which will reduce pH and increase acidity.

Increasing temperature favours the right side of reaction producing more H+ and OH-, this does not reduce electrical conductivity.

44. D

Aluminium has 13 electrons so the Al2+ ion will have 11. This corresponds to the following configuration 1s22s22p63s1

45. C

Atomic number = 12 corresponds to magnesium which has a 2+ valency. Atomic number 9 corresponds to fluorine which has a valency of minus 1-. Thus if X = 12 and Y = 9 we will get XY2

46. E

If the chains in the molecules are longer and less branched then the boiling point will increase, as it results in stronger induced dipoles. Pentane is longer and less branched in this case. 

47. C

CrO4 would have a collective oxidation number of -2 (+6 from Cr, -8 from the four O). Ammonia as you should know has an oxidation number of +1 (or you could see this from N having -3 and the four H have +4 in total). Thus we will need 2 NH4 to balance the CrO4 and get a molecule with no net charge. C is thus correct.

48. E

Propanal is an aldehyde with three carbons, this corresponds to CH3CH2CHO

49. D

This is a combustion reaction so you should be able to draw out the following reaction, C3H7OH + O2→ H2O + CO2. This just needs to be balanced which becomes 2C3H7OH + 9O2→ 8H2O + 6CO2

We can see from the balanced equation that the ratio of CO2 to H2O is 3:4

50. D

here will have been 60g of potassium nitrate dissolved in the original solution. To dissolve this amount fully at the lower temperature, there must be 60/50 x 100g water = 120g. This means 70g must be added to the solution in order for all the potassium nitrate to be dissolved.

51. E

CO2 will produce carbonic acid in water and SO2 will produce sulfuric acid in water. CO and NO will not produce acid. 

52. D

We need to find which compound when dissolved in water is basic. Carbonates will be basic in water, and in option D we have sodium carbonate.

53. A

2log10(x) can be rewritten as log10(x2). 

log10(x2) – log10(y) = 3 can be rewritten as log10(x2/y) = 3

We can then rewrite this as x2/y = 1000, which can be rewritten as y = x2/1000

54. E

Current = voltage/resistance and current = charge/time

(V/R1 ) + (Q/t) are represent voltage/resistance and charge/time, so the units are consistent on the left and ride side for option E

55. A

These are two simultaneous equations. Sub y = 2x– 5 into the top equation and we will get that 7x– 15 = 13. This means that x = 4

We then sub this into the bottom equation to get y = 2(4) – 5 so y = 3

x + y = 4 + 3 = 7

56. D

The centripetal force of an object in circular motion is pointed towards the centre of the circle, which is given by the direction R. This rules out all options besides A and D. 

The centripetal force is mv2/r, which is (1000 x 302)/50 which is equal to 18,000N. This is the same as 18kN

57. D

We are told the mean of a, b, c is 8 which means that (a + b + c)/3 = 8 

This means a + b + c = 24 

We now want to get the mean of   a + 1, b + 2, c + 6, 3. First replace 1, 2, 6 and 3 with 12

(a + b + c + 12)/4 = mean

Therefore mean = 36/4 = 9

58. B

Here you just need to convert the squared numbers into whole numbers and solve…

(729– 529) + (196– 36) = 200 + 160 = 360

59. D

Energy = mass x specific heat capacity x temperature change. 

This means specific heat capacity = energy/(mass x temperature change) 

This is equal to 9000/(2.5 x 4) J/(kgK) 

60. E

Since there are two forces acting on a beam, the torques magnitude acting on the beam will be the two forces combined. 

Since the pivot is in the centre and the forces act at the end of the beam then torque = 2 x (F x d)/2 = F x d. This eliminates A and D

The forces must be acting in opposite directions, which eliminates C. 

B is eliminated as there would be no moments if we just pull horizontally on both sides. 

E is the only option left