Marco Invests $760 into a savings account. The account pays 4% simple interest. A. How much interest will he earn after 5 years? B. If Marco makes no deposits or withdrawals to his account in 5 years. How much will be in that account in 5 years?

Part A)

Part B)

Step-by-step explanation:

Part A) How much interest will he earn after 5 years?

we know that

The simple interest formula is equal to

where

A is the Final Investment Value

I is the Final Interest Value

P is the Principal amount of money to be invested

r is the rate of interest  

t is Number of Time Periods

in this problem we have

substitute in the formula above

Part B) If Marco makes no deposits or withdrawals to his account in 5 years. How much will be in that account in 5 years?

we know that

The final investment value will be equal to the initial deposit plus the interest

so

we have

substitute

1/4 and 8/3 because:

the reciprocal if 4 is 1/4 because 4 is used as 4/1 and the opposite of that is 1/4. the opposite of 3/8 is 8/3 so that is the answer.