If the purchase price of a big schoolbag and a small schoolbag is X and Y respectively, then X-Y is 60.

Selling at a profit of 20%, the big schoolbag and the small schoolbag are equivalent to 0.2x and 0.2y respectively, so the profit difference is:

0.2x-0.2y=0.2*60= 12 yuan.

When the big schoolbag is sold at a 10% discount, it is discounted on the basis of the selling price. =0.9*( 1+0.2)x

Then the profit is 0.9 * (1+0.2) x-x = 2/25 * x = 0.08x.

0.08x-0.2y=0.08*y+0.08*60-0.2y

It depends here. When y & gt40 points, the big bag makes less money than the small bag, and when y < 40 points, the big bag makes more money.