TYPE III: FINDING THE BASE
In type III problems, you are given the part and rate and are asked to find the
base or whole.
EXAMPLE:A salesperson earns a 15% commission on all sales. If the
commission was $1125, find the amount of his sales.
SOLUTION:
GOAL: You are being asked to find the total amount of sales.
STRATEGY: In this type of problem, you are given the part (commission)
and the rate. Place $1125 in the top portion of the circle and the 15% in the
bottom left portion. UseB¼PR. See Figure 5-5.
IMPLEMENTATION:
B¼
P
R
B¼
1125
15 %
¼
1125
0 : 15
¼$ 7500
The total sales were $7500.
EVALUATION: To check the answer, find 15% of $7500: 0.15 7500 ¼
$1125. Hence, the answer is correct.
Some percent problems involve finding a percent increase or decrease.
Always remember that the original value is used as the base and the amount
Fig. 5-5.LESSON 5 Using Percents 47