# If the C.P. of 11 shirts is equal to the S.P. of 10 shirts, find the % profit or loss.

C.P. (Cost price) of 11 shirts equals S.P. (selling price) of 10 shirts. If it equals *x*, the cost of one shirt is `x/11` and the selling price of one shirt is `x/10` . Since 1/10 is greater than 1/11, the selling price is greater than the cost price, so there will be profit.

The percentage of profit is the ratio of money made by selling one shirt (selling price - cost price) to the selling price:

% profit = `(x/10-x/11)/(x/10) *100%`

Simplify this fraction by multiplying numerator and denominator by 11*10:

`(11*x -10*x)/(11*x) *100% =1/11 *100% =9.09%`

**So profit percentage is 9.09%.**

Let the CP of 11 shirts = x

Therefore CP of 1 shirt = x/11

SP of 10 shirts = x ( Given that CP of 11 shirts is same as SP of 10 shirts)

Therefore SP of 1 shirt = x/10

Profit on 1 Shirt = SP – CP

= x/10 - x/11

= ( 11x-10x )/110

= x/110

Profit % = Profit / CP X 100

= ( x/110 / x/11 ) x 100

= ( 11/110 )x 100

= 10