Use the formula I=prt to solve.

1. Basil earned $631.40 in 7 years on an investment at a 5.5% simple interest rate.

How much was Basil's investment?

A. $496

B. $1640

C. $16,400

D. $80,360

2. Jennifer earned $249.60 in 612 years on a $640 investment.

What was the simple interest rate?

A. 3.9%

B. 6%

C. 39%

D. 62.4%

1. The correct answer is B. $ 1,640

2. The correct answer is B. 6%

Step-by-step explanation:

1. Let's review the information provided to answer to us to answer the question correctly:

Interest earned = $ 631.40

Time of investment = 7 years

Interest rate = 5.5% simple interest rate = 0.055

How much was Basil's investment?

For answering the question, let's use the formula given, this way:

I=prt

Replacing with the values we know:

631.40 = p * 0.055 * 7

631.40 = 0.385p

p = 631.40/0.385

p = $ 1,640

The correct answer is B. $ 1,640

2. 1. Let's review the information provided to answer to us to answer the question correctly:

Interest earned = $ 249.60

Time of investment = 6 1/2 years = 6.5

Amount of investment = $ 640

What was the simple interest rate?

For answering the question, let's use the formula given, this way:

I=prt

Replacing with the values we know:

249.60 = 640 * r * 6.5

249.60 = 4,160r

r = 249.60/4,160

r = 0.06

The correct answer is B. 6%