Question

The Lombardo family went out to dinner and the cost of their meal was $62. If they left a 20% tip, how much did they leave?

Answer 1

The Lombardos left a tip of `$12.40`

Explanation:

If you know how to find `10%` of any number, you can use logic to find any other percent.

`10%` of any number is found by moving the decimal point one step smaller.

So `10%` of `$62` is `$6.20`

By logic, if `10%` is `$6.20`, then `20%` must be twice as much -- namely `$12.40`

Answer:
They left a tip of `$12.40`

Check

`20% "of"  $62` should equal `$12.40`

`color(white)(mml.)` `$62`
`color(white)(m)` `xx 0.20`
`color(white)(mm)`―――
`color(white)(mml)` `124 0`

Put the decimal point in place
`$12.40`

`Check`

Answer 2

They left a $12.40 tip.

Explanation:

Discarding tax and any other surcharges (since none were specified,) we know that they left a tip of $12.40

To get this answer, first convert 20% to decimal form by replacing the percentage sign with a decimal point and moving it two places to the left

`20%` becomes `20.0` which becomes `.200`
Let this be known as `p`

Next, let `c` represent cost and `x` represent the tip (in dollars) left. Plug in the information to the equation `c*p = x`

`62*.20 = 12.40`