peter spent 20% of his money. he has $40 left in his pocket . how much did he go out with.

0.8x = 40

x = $__________

20/100 × ×=40

$50

To find out how much Peter had before he spent 20% of his money, we can set up an equation.

Let's say Peter's original amount of money is represented by 'x'. Since he spent 20% of his money, he would have 80% (or 0.8) of his money left, which is equal to $40.

So, the equation will be: 0.8x = $40

To find 'x', we need to isolate it on one side of the equation. We can do this by dividing both sides of the equation by 0.8:

0.8x / 0.8 = $40 / 0.8

x = $50

Therefore, Peter initially had $50 before he spent 20% of his money.