Question

what is 80 per cent of a number whose 200 per cent is 90

Answer 1

Let the number be 'x'

200/100 *x=90

2x=90

x=45

80% of 45= 0.8*45=36

Answer 2

let the number be x
so, 200%×x/100= 90
2x= 90
x= 90/2
x= 90/2= 45

find 80% of number
so, 80×45/100

=36