Question

90 is 20% more than what?

Answer 1

See full explanation below:

Explanation:

We can write this as:

`90 = x + (20%` of `x)`

"Percent" or "%" means "out of 100" or "per 100", Therefore 20% can be written as `20/100`.

When dealing with percents the word "of" means "times" or "to multiply".

So we can rewrite the equation as and solve for `x`:

`90 = x + (20/100 xx x)`

`90 = x + 20/100x`

`90 = 100/100x + 20/100x`

`90 = 120/100x`

`color(red)(100)/color(blue)(120) xx 90 = color(red)(100)/color(blue)(120) xx 120/100x`

`9000/color(blue)(120) = cancel(color(red)(100))/cancel(color(blue)(120)) xx color(blue)(cancel(color(black)(120)))/color(red)(cancel(color(black)(100)))x`

`75 = x`

`x = 75`

90 is 20% more than 75