ICAP QAT: Quantitative Aptitude

What the domain tests

The ICAP QAT Quantitative Aptitude domain checks whether you can turn a short numerical problem into the right arithmetic relationship and solve it accurately under time pressure. Expect percentages, ratios and proportions, averages, simple and compound interest, profit and loss, speed–distance–time, work rates, basic algebra, and interpretation of tables or charts. The exam rewards clean setup and estimation as much as long calculation.

Core rules to keep ready

• Percentage change = (new − old) ÷ old × 100. A 20% increase followed by a 20% decrease is not zero: 100 → 120 → 96, a net 4% fall.
• Ratio sharing: if A:B = 3:5, total parts = 8; each part = total ÷ 8.
• Average = sum ÷ count, so sum = average × count. Weighted averages use the counts as weights.
• Simple interest = P × r × t; compound amount = P(1 + r)^t when r is a decimal annual rate and t is years.
• Work: combined rate = 1/a + 1/b; time together = ab/(a + b) for two workers.
• Speed: distance = speed × time; convert km/h to m/s by multiplying by 5/18.

Worked example

A trader marks an item at Rs 800, gives a 15% discount, and still makes a 20% profit on cost. What is the cost? Discounted price = 800 × 0.85 = Rs 680. Profit is on cost, so selling price = 1.20 × cost. Cost = 680 ÷ 1.20 = Rs 566.67. Check: 566.67 × 1.20 = 680, and 680 is 85% of 800.

Traps that cost marks

Do not apply profit percentage to the marked price when it is stated “on cost”. Do not average percentages without weighting. In interest, keep r and t in the same units. In ratio questions, add the parts before dividing. Estimate first to catch place-value errors.