How the AMCAT quantitative modules work
You sit one of the two quantitative modules. Both share the core topics of school arithmetic and number theory, set as short problems about prices, interest, trains, work and shares. Quantitative Ability Tech has two more questions and adds the engineering maths topics: powers, logarithms, permutations and combinations, and probability. AMCAT does not say who gets which; check your admit card or invitation.
Like every AMCAT module, it is adaptive. A correct answer brings a tougher question, your score depends on the level of the questions you get right, and there is no negative marking.
A method for each topic
Most questions fall to one standard step:
- Profit and loss: call the cost price 100. A mark-up and a discount then become a single multiplication.
- Simple and compound interest: write the rate as a multiplier (8% a year is 1.08) and multiply once for each year for compound interest.
- Speed, distance and time: put everything in the same units first. To go from km/h to m/s, multiply by 5 and divide by 18.
- HCF and LCM: things that happen together again (bells, laps, signals) need an LCM; the largest equal share, tile or group needs an HCF.
- Inverse proportion: more workers, fewer days. Multiply workers by days to get the total work, then divide by the new number of workers.
- Probability: count the outcomes you want and divide by all the outcomes. List them when there are fewer than about forty.
Worked examples
Profit and loss. A shopkeeper marks a fan 25% above its cost price and gives a 10% discount. What is his profit percentage? Options: 10%, 12.5%, 15%, 22.5%.
Call the cost 100. The marked price is 125, and 10% off 125 is 112.5. The profit is 12.5 on 100, so 12.5%. The trap is 15%, from subtracting 10 from 25.
HCF and LCM. Three bells ring every 12, 18 and 30 minutes. They ring together at 9:00 am. When do they next ring together? Options: 10:30 am, 11:00 am, 12:00 noon, 3:00 pm.
You need the LCM of 12, 18 and 30. 12 is 2 × 2 × 3, 18 is 2 × 3 × 3 and 30 is 2 × 3 × 5, so the LCM is 2 × 2 × 3 × 3 × 5 = 180 minutes, three hours. The answer is 12:00 noon.
Probability, on the Tech module. Two dice are thrown. What is the probability that the total is a prime number? Options: 1/3, 5/12, 1/2, 7/12.
The prime totals are 2, 3, 5, 7 and 11. They can be made in 1, 2, 4, 6 and 2 ways, which is 15 of the 36 outcomes. 15/36 is 5/12.
Tips for the real quantitative module
- Keep paper and a pen ready and plan for no calculator, because AMCAT does not say one is allowed.
- Estimate before you calculate. If the options are far apart, a rough answer picks the right one in seconds.
- Learn the squares to 25, the cubes to 10 and the fractions of 100 (1/8 is 12.5) so you never work them out under the clock.
- Do not spend three minutes on one question. Make your best choice and move on: there is no negative marking.
- If your stream gets the Tech module, revise logarithm rules and the formulas for nPr and nCr before the day.
Practise AMCAT Quantitative Ability on CogniPrep
Choose either module at the start: Quantitative Ability with 14 questions or Quantitative Ability Tech with 16, both on a 20-minute clock. Questions come one at a time with no Back, no skip and no calculator, adapting on a five-level scale, and questions you do not reach count as wrong. Your result gives a percentile against other CogniPrep users who took the same module, your accuracy topic by topic and the highest level you answered correctly. The difficulty levels are our estimates.