Question

Question #3e18e

Answer 1

`$143.75`

Explanation:

The problem tells you that Mrs. Margul wants to leave a `15%` tip to her hairdresser, so the first thing to do here is to use this information to calculate the value of the tip.

Now, a `color(blue)(15)color(darkgreen)(%)` tip basically means that Mrs. Margul will pay `color(blue)($15)` for every `color(darkgreen)($100)` in her bill. In essence, you can treat a percentage as a conversion factor to take you from the value of the bill to the value of the tip or vice versa.

In this case, the bill is `$125`, so Mrs. Margul will have to add a tip of

`$125 color(red)(cancel(color(black)("bill"))) * color(blue)("$15 tip")/(color(darkgreen)("$100" color(red)(cancel(color(black)("bill"))))) = "$18.75 tip"`

This means that the total bill, i.e. bill + tip, will amount to

`"total bill" = $125 + $18.75 = $143.75`