Question

130% of what number is 1170?

Answer 1

`900`

Explanation:

As the number has been increased by 30% to become 1170, we are expecting a number smaller than 1170 as the answer.

DO NOT be tempted to just subtract 30%. 30% of a smaller number is not the same as 30% of a larger number.

One method is to write an equation stating exactly what is asked in the question. "130% of some number is 1170."

`130/100 xx x = 1170`

`x = 1170 xx100/130 " by dividing by 130, we are finding 1%"`

`x = 900`

OR, by direct proportion:

`130/100 = 1170/x`

`x = (100 xx 1170)/130`

`x=900`

[Quick check: 130% =1.3 so `900 xx 1.3 = 1170`]