The average cost price of articles 'X' and 'Y' together is

Solution

ATQ,

Let the cost price of article 'X' = Rs. '10x'

Then, cost price of article 'Y' = Rs. (10x + 80)

Sum of cost price of articles 'X' and 'Y' = 10x + 10x + 80 = Rs. (20x + 80) = 400 × 2

Or, 20x + 80 = 800

Or, 20x = 720

Or, x = 36

Cost price of articles 'X' and 'Y' are Rs. 360 and Rs. 440, respectively

Selling price of article 'X' = 360 × 1.1 = Rs. 396

Selling price of article 'Y' = 440 × 1.2 = Rs. 528

Required difference = 528 - 396 = Rs. 132