A shopkeeper sells two articles, A and
B. The ratio of the cost price of A and B is 4:5, respectively. The marked price of A is thrice the marked price of
B. The selling price of A is Rs 840, which is Rs 840 more than the discount offered on it. What is the profit earned on B (in Rs)? I: The cost price of A is Rs 700, and the profit earned on B is 20% of its cost price. II: The selling price of A is Rs 665 more than the profit earned on
B.

Let the cost price of A and B be 4a and 5a respectively. Let the marked price of A and B be 3b and b respectively. Selling price of A = Rs 840 The selling price of A is Rs 840, which is Rs 840 more than the discount offered on it So, discount offered is 0 3b – 0 = 840 3b = 840 b = 280 The marked price of A and B be Rs 840 and Rs 280 respectively. I: The cost price of A = Rs 700 The cost price of B = 700 × 5 4 = Rs 875 The profit earned on B = 875 × 20 100 = Rs 175 I is sufficient. II: The selling price of A = Rs 840 Profit earned on B = 840 – 665 = Rs 175 II is sufficient.