Page 202 - Math Course 1 (Book 1)

Using Percent Equations

Let’s Begin I = prt Write the simple interest
formula.

495 = 2000(0.045)t Replace I with 495, p with
Find Discount 2000, and r with 0.045.
495 = 90t Simplify.
Example 495 90t Divide each side by 90.
90 = 90

JEWELRY 5.5 = 5 Simplify.
The regular price of a ring is $495. It is on sale at a
20% discount. What is the sale price of the ring?
It will take 5.5 years to
1 Answer earn $495.
Estimate : of 500 = 100
5
Method 1
First, use the percent equation to f nd 20% of 495.
Let d represent the discount. Your Turn!

d = 0.20(495) The whole is 495 and the percent Find Discount
is 20.
RETAIL
= 99 Simplify. The regular price of a stereo system is $1295. The
system is on sale at a 15% discount. Find the sale
Then, f nd the sale price. price of the stereo system.

495 – 99 = 396 Subtract the discount from the A. $194.25
original price. B. $1100.75
Method 2 C. $1170.00
A discount of 20% means the ring will cost 100%– D. $1489.25
20%or 80% of the original price. Use the percent Answer
equation to f nd 80% of 495.

Let s represent the sale price.

s = 0.80(495) The whole is 495 and the percent
is 80%.
s = 396

Find Discount
The sale price of the ring will
Answer BANKING
be $396. Suppose you invest $3500 at an annual interest
rate of 6.25%. How long will it take for it to earn
$875?
Apply Simple Interest Formula
A. 64 years
B. 55 years
Example C. 4 years
D. 0.4 years
BANKING Answer
Suppose you invest $2000 at an annual interest rate
of 4.5%. How long will it take for it to earn $495 in
interest?

Interest(I) = Amount(P) • Interest rate(r) • Time(t)

194