Question

Frances left a 10​% tip on a meal. Including the​ tip, its cost was​ $24.20. What was the cost of the meal before the​ tip?

Answer 1

`$22`

Explanation:

The total is equal to the cost of the meal plus the cost of the meal times the ten percent which would equal the tip.

`x=` the cost of the meal

`x * 10% =` the tip

So

`$24.20=x10%+x`

`24.2=x* 0.1+x" " ->` `10% = 10/100`

`24.2=x(0.1+1)`

`24.2=1.1x`

`24.2/1.1=x`

`x=22`

Answer 2

The meal itself cost `$22`

Explanation:

This is an example of reverse percentage because you know the value AFTER an increase of `10%` has taken place, but you do not know the original amount.

You can use direct proportion to compare the corresponding values and percentages.

The cost of just the meal, `x,` represents `100%`

Once a tip of `10%` is added on, the value represents `110%`

We know that is `$24.20`

`x/100 = 24.20/110" "(larr "dollars")/(larr "percent")`

`x = (24.20 xx100)/110`

`x= $22`

Check.:

`10%` of `$22 = $2.20`

`$22+$2.20 = $24.20`