GO Classes 2023 | IIITH Mock Test 1 | Question: 86

Answer 1

Answer: C

Assume merchant buy $x$ number of products

Cost prize of $x$ items = $20x$

Selling prize of $x$ items = $\frac{x}{2}(2*2 + (x-1)*2) \implies \frac{x}{2}(4+2x-2) \implies x(x+1)$

Profit percentage = $40 \%$

$\frac{x(x+1) – 20x}{20x} = 0.4 \implies x-19 = 8 \implies x = 27$

Answer 2

Let us assume he buys n goods.

Total CP = 20n

Total SP = 2 + 4 + 6 + 8 ….n terms

Total SP should be at least 40% more than total CP

2 + 4 + 6 + 8 ….n terms ≥ 1.4 * 20 n

2 (1 + 2 + 3 + ….n terms) ≥ 28n

n(n + 1) ≥ 28n

n2 + n ≥ 28n

n2 - 27n ≥ 0

n ≥ 27