Question

A number, on subtracting 15

from it, reduces to its 80%. What

is 40% of the number?

Answer 1

The 40%of the number=30
Let no. be x
So,80%of x=4/5x
A/Q x-15=4/5x
x+4/5x=15
5x-4x=15×5
x=75

40% of x=75/100×40
=30 Ans

Answer 2

Let the no. be x
x-15=x-80/100x
x-15=x-4x/5
x-15=x/5
x=75/4
now,
40% of no.
75/4×40/100
7.5