GMA Quantitative Reasoning 2 — Questions and Answers

Question 1: A product costs $80. It is marked up by 25%, then discounted by 20%. What is the final price?

$76
$80 (Correct answer)
$84
$88

Correct answer: $80

After 25% markup: $80×1.25=$100. After 20% discount: $100×0.80=$80. The final price is $80.

Sequential percentage changes are multiplicative. Step 1 (markup 25%): $80 × 1.25 = $100. Step 2 (discount 20%): $100 × 0.80 = $80. The item returns to its original price. This is a common trap: a 25% increase followed by a 20% decrease does NOT cancel out symmetrically (that would require a 25% decrease to cancel the 25% increase).

Question 2: The ratio of boys to girls in a class is 3:2. If there are 30 students total, how many girls are there?

10
12 (Correct answer)
15
18

Correct answer: 12

Total ratio parts: 3+2=5. Girls = (2/5)×30=12.

The ratio 3:2 means boys form 3/(3+2)=3/5 of the class and girls form 2/5. Total students=30. Girls = (2/5)×30=12. Boys = (3/5)×30=18. Check: 12+18=30 ✓.

Question 3: If 15% of a number is 45, what is 40% of the same number?

100
110
120 (Correct answer)
130

Correct answer: 120

First find the number: 15% = 45, so 100% = 45÷0.15 = 300. Then 40% of 300 = 120.

Step 1: If 15% of N = 45, then N = 45/0.15 = 300. Step 2: 40% of 300 = 0.40 × 300 = 120. Alternatively, since 40% = (40/15)×15%, the answer is (40/15)×45 = 2.667×45 = 120.

Question 4: A rectangle has area 48 m² and width 6 m. What is its perimeter?

22 m
24 m
28 m (Correct answer)
32 m

Correct answer: 28 m

Length = Area ÷ Width = 48÷6 = 8 m. Perimeter = 2×(length+width) = 2×(8+6) = 2×14 = 28 m.

Area of rectangle = length × width. So length = 48÷6 = 8 m. Perimeter = 2(L+W) = 2(8+6) = 2(14) = 28 m. This two-step problem requires using the area formula to find a missing dimension before calculating the perimeter.

Question 5: A sum of $1,200 is invested at a simple interest rate of 5% per year. How much interest is earned after 3 years?

$150
$180 (Correct answer)
$200
$60

Correct answer: $180

Simple interest = Principal × Rate × Time = $1,200 × 0.05 × 3 = $180.

Simple interest is calculated on the original principal only (unlike compound interest). Formula: I = P × r × t = $1,200 × 0.05 × 3 = $180. The total amount after 3 years would be $1,200+$180=$1,380. Note: this is NOT compound interest.

Question 6: A shop offers buy-2-get-1-free on items priced $15 each. If you buy 6 items, how much do you pay?

$60 (Correct answer)
$75
$90
$45

Correct answer: $60

Buy-2-get-1-free means every 3 items cost 2×$15=$30. For 6 items (two groups of 3): 2×$30=$60.

With buy-2-get-1-free, for every 3 items you only pay for 2. 6 items form 2 groups of 3. Each group costs 2×$15=$30. Total cost = 2×$30=$60. This is equivalent to paying for 4 items out of 6: 4×$15=$60. The effective discount is 2 free items ($30) off the $90 full price.

GMA Quantitative Reasoning 2

A product costs $80.
It is marked up by 25%, then discounted by 20%.
What is the final price?