Compound Interest Formulas

The compound interest formula is:

B = p(1 + r)^t

What does the B represent?

• The amount of interest earned.

• The amount of time that has passed.

• The total amount of money after a certain amount of time.

• The amount required to invest.

Caiden earned $475 from mowing lawns last summer. He deposited this money in an account that pays an interest rate of 3.8% compounded annually. What will be his balance after 15 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $827.52

• $831.10

• $839.45

• $846.80

Erik has $40 in a savings account that earns 5% interest, compounded annually.

To the nearest cent, how much will he have in 2 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $44

• $44.10

• $34.10

• $24.10

Elizabeth has $20 in a savings account. The interest rate is 5%, compounded annually.

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $2.00

• $2.05

• $2.10

• $2.50

Mike deposited $70 in a savings account earning 10% interest, compounded annually.

To the nearest cent, how much will he have in 3 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $93.00

• $93.17

• $103.17

• $113.17

Nolan has $5 in a savings account. The interest rate is 10%, compounded annually.

To the nearest cent, how much interest will he earn in 3 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $1,67

• $1.66

• $1.68

• $1.70

Britney deposited $30 in a savings account earning 5% interest, compounded annually.

To the nearest cent, how much will she have in 2 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $33.00

• $33.08

• $34.08

• $30.00

Candice has $80 in a savings account that earns 5% interest, compounded annually.

To the nearest cent, how much interest will she earn in 3 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $12.60

• $12.61

• $12.62

• $12.00

Leo has $50 in a savings account. The interest rate is 5%, compounded annually.

To the nearest cent, how much will he have in 3 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $57.00

• $57.88

• $57.89

• $60.00

Shereen has $80 in a savings account. The interest rate is 10%, compounded annually.

To the nearest cent, how much interest will she earn in 3 years?

Use the formula B = p(1 + r)^t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

• $26.47

• $26.48

• $26.50

• $26.00