# GED Math : Proportions and Percentages

## Example Questions

### Example Question #21 : Proportions And Percentages

To get on the ballot for the student body president at McKinley High School, a student must turn in a petition with the signatures of 8% of the students from each of the three classes - sophomore, junior, and senior. There are 429 sophomores, 355 juniors, and 322 seniors enrolled at McKinley.

Greg has a petition with the signatures of 35 sophomores, 30 juniors, and 24 seniors. Can he get on the ballot with the signatures he has, and if not, why not?

Greg has the signatures he needs to get on the ballot.

Greg cannot get on the ballot yet, because he needs more signatures from sophomores.

Greg cannot get on the ballot yet, because he needs more signatures from juniors.

Greg cannot get on the ballot yet, because he needs more signatures from seniors.

Greg cannot get on the ballot yet, because he needs more signatures from seniors.

Explanation:

In order to answer the question, we must find out the percent of each class that has signed Greg's petition, and compare it to 8%.

Sophomores: 35 out of 429, which is  of the sophomores.

Juniors: 30 out of 355,which is  of the juniors.

Seniors: 24 out of 322, which is  of the seniors.

Greg has sufficient signatures from sophomores and juniors, but not seniors.

### Example Question #22 : Proportions And Percentages

Above is the menu for a coffee shop. The shop charges 7% sales tax.

Clara orders two large iced coffees, one large cappucino, one large cafe latte, and four butter croissants. She hands the cashier a twenty-dollar bill and a ten-dollar bill. How much will Clara get back in change?

The amount Clara has paid is insufficient.

Explanation:

Add up the pretax prices of Clara's items to find the total pretax amaount:

The tax is 7% of this, or

, rounded to the nearest cent.

Add the amounts to get the cost after tax:

### Example Question #30 : Proportions And Percentages

Refer to the above diagram. The circles are of equal size and the portions of each circle are of equal size.

If the shaded portion of the circle at lower right were to be unshaded, then by what percent would the area of the unshaded region increase?