Question

the cost price of an article is 90% of its selling price find his profit percentage

Answer 1

the answer is 11.11
let the selling price be 100
then the cost will be 90
so the profit is (10÷90)×100
=11.1111

Answer 2

Let cost price =C
let Selling Price=S
Given:
90/100 *S=C.
C=0.9S.

therefore profit %= S-0.9S/ 0.9S ×100
= 0.1S/0.9S ×100
=100/9%
=11 1/9%(Ans)