Question

The balance in an account earning simple interest varies jointly with principal (the amount invested), the annual interest rate, and time measured in years with a constant of proportionality of 1. If you receive $10,000 from a rich uncle for a graduation gift and invest it in a certificate of deposit that pays 5% simple interest for 50 years (approximately the number of years before you retire), how much will the account then be worth?

After 50 years, the certificate of deposit will be worth

Answer 1

$35000

Explanation:

account worth = deposit + simple interest

/ 100

 intrest = deposit x year x simple interest

10000×50×5/100=25000

account worth = deposit + simple interest

 = 10000 + 25000

 = $ 35000

Answer 2

Answer: $100,000

Explanation:

$100,000. This is because the balance in the account varies jointly with principal, the annual interest rate, and time measured in years with a constant of proportionality of 1. Therefore, the balance in the account at the end of 50 years is 10,000 × 1 × (1 + 0.05)50, which is equal to $100,000.