A shopkeeper bought two watches at Rs 500. he sold one at loss of 12%and other at the profit of 8%. he neither gained nor loss at this transaction. Find the cost price

Step-by-step explanation:

Let CP of one watch = x

CP of second watch = 500 - x

SP of first watch = (100-12) % of x = 88% of x=0.88x

SP of second watch = (100+8) % of (500 - x) = 108% of (500 - x)

= 1.08 * (500 - x) = 1.08*500 - 1.08*x

= 540 - 1.08x

Sp of two watches = 500

0.88x + 540 - 1.08x = 500

-0.20x + 540 = 500

-0.20x = 500 - 540

-0.20x = - 40

x = - 40/-0.20 = 40*100/20 = 2*100 = 200

CP of first watch = 200

CP of second watch = 500 - 200 = 300