Both A and B sells their watch at the rate of Rs.5,400 per watch. A earned a profit of 10 percent while B incurred a loss of 25 percent. What is the ratio of cost prices of A and B?

15 : 22

A earned 10%

B loses 25%

         CP                      SP

A       10                      11

B       4                         3

As the selling price for both A and B is same then multiply A by 3 and B by 11

         CP                      SP

A       10                      11)×3

B       4                         3)×11

         CP                      SP

A       30                      33

B       44                      33

So the ratio of cost price of A and B is

30 : 44 = 15 : 22