Question

what would happen to the two future value numbers and the difference between them if the two accounts did not pay interest

Answer 1

There would be no difference between the present values of the numbers and their future values, if the two accounts did not pay any interest.

For example, let us consider the two accounts, with $7 being deposited into one account, and $ 9 being deposited into another account.. And let us also assume that the time period n = 4 years. And interest rate r is 0 %.

Future Value = Present Vaue ( 1 + r ) ⁿ

Future value of $ 7 = $ 7 * ( 1 + 0) ⁴ = $ 7

Future value of $ 9 = $ 9 ( 1 + 0 )⁴ = $ 9

The difference between the two numbers also remains the same at $ 2.