﻿

# ASVAB AFQT For Dummies by Rod Powers Author:Rod Powers
Language: eng
Format: epub
ISBN: 9781118813997
Publisher: Wiley
Published: 2014-05-22T18:20:52+00:00

You now have two equations, with two variables that you can use to solve the problem:

Replace s in the second equation with the definition of s in the first equation:

Mary is 20 years old. That’s the same answer you get when you use the one-variable solution in the preceding section.

Geometric problems

These problems require you to compute the volume, perimeter, area, circumference, diameter, and so on of various geometric shapes.

You’re painting a fence that is 20 feet long and 6 feet high. How much square footage of fence are you covering with paint?

The area formula for a rectangle is a = lw, so the answer to this simple problem is a = 6 · 20 = 120 square feet.

Generally, the Arithmetic Reasoning test makers don’t let you off so easy, though. The problem is more likely to be written something like the following.

You’re painting a fence that is 20 feet long and 6 feet high. Paint costs \$7.23 per gallon, and 1 gallon of paint covers 60 square feet of fence. How much do you need to spend on paint to complete the project?

The problem now requires a couple of extra steps to answer. First, you have to compute the area of the fence. You already did that: 120 square feet.

Now you have to determine how many gallons of paint you need to buy to cover 120 square feet. Because 1 gallon of paint covers 60 square feet, you need 120 ÷ 60 = 2 gallons of paint.

Finally, you need to figure how much 2 gallons of paint cost. Paint is \$7.23 per gallon, and you need 2 gallons, so \$7.23 · 2 = \$14.46.

You get quite a few geometric problems on the Arithmetic Reasoning subtest. To make sure you’re ready for them, memorize the basic geometric formulas in Table 10-1. You can find more information about using these formulas in Chapter 8.

Table 10-1 Basic Geometric Formulas

Shape

Function

Formula 