we can also say this in another way ... (8% of what number is 12?)
let a be the number of which 8 % is 12 ....
8/100 x a =12 
a=12 x 100/8 
a=(6/4) x 100 
a=(3/2) X 100
a = 150 
now if u want to check your answer.. substitute the value of a .....
(8/100) x 150=12 ....
Hope it helps !!!