Question

What percentage is rs15 of rs120?

Answer 1

120×x/100= 15
or, x = 1500/120
or x = 12.5% .is right answer.

Answer 2

Let the % be x
Then
100%/x%=120/15
(100/x)*x=(120/15)*x      
100=8*x      
100/8=x 
12.5=x 
x=12.5

now we have: 
15 is 12.5% of 120