Education.com

# Logic and Venn Diagrams for CBEST Exam Study Guide

By LearningExpress Editors
LearningExpress, LLC

You deserve a break after all your hard work on math problems. This lesson is shorter than the others; unless logic problems give you a lot of trouble, you can probably spend less than half an hour on this lesson

### If Problems

If problems are among the easiest problems on the test if you know how to work them. A genuine If problem begins with the word If and then gives some kind of rule. Generally, these problems mention no numbers. In order for the problem to be valid, the rule has to be true for any numbers you put in.

#### Sample If Question

The following is a typical if problem. Experiment with this problem to see how the answer is always the same no matter what measurements you choose to use.

1. If the length and width of a rectangle are doubled, the area is
1. doubled.
2. halved.
3. multiplied by 3.
4. multiplied by 4.
5. divided by 4.

First of all, choose a length and width for your rectangle, like 2' by 3'. The area is 2 × 3, or 6 square feet. Now double the length and the width and find the area: 4 × 6 = 24 square feet. Twenty-four is 4 times 6, so choice d must be the answer. Try a few different numbers for the original length and width to see how easy these types of questions can be.

#### Practice

Try another one:

1. If a coat was reduced 20% and then further reduced 20%, what is the total percent discount off the original price?
1. 28%
2. 36%
3. 40%
4. 44%
5. 50%
##### Hot Tip

When choosing numbers for if problems, choose small numbers. When working with percents, start with 100.

Since this question concerns percents, make the coat's beginning price \$100. A 20% discount will reduce the cost to \$80. The second time 20% is taken off, it is taken off \$80, not \$100. Twenty percent of 80 is 16. That brings the cost down to \$64 (80 – 16 = 64). The original price of the coat, 100, minus 64 is 36. One hundred down to 64 is a 36% reduction. So two successive discounts of 20% equal not a 40%, but a 36% total reduction.

### Ask a Question

150 Characters allowed

### Related Questions

#### Q:

See More Questions

### Today on Education.com

#### WORKBOOKS

May Workbooks are Here!

#### WE'VE GOT A GREAT ROUND-UP OF ACTIVITIES PERFECT FOR LONG WEEKENDS, STAYCATIONS, VACATIONS ... OR JUST SOME GOOD OLD-FASHIONED FUN!

Get Outside! 10 Playful Activities

## Special Editions

### Browse by Grade

#### Washington Virtual Academies

Tuition-free online school for Washington students.