Question

Charlie finished 7 laps around the track, This is 20% of the number of laps he has to do. How many laps must he do?

Answer 1

`"Target lap count is "35`

Explanation:

Let the target lap count be `x`

Then 7 laps = 20% of `x`

`7=20/100x`

but `20/100 = 1/5`

`7=x/5`

Multiply both sides by 5

`7xx5 = x xx 5/5`

But `5/5=1" and "7xx5 = 35`

`35=x`

`x=35`