Time Value of Money Solution Grid: Additional Problems

These are additional time value of money problems using the money solution grid. For more information, make sure you review the Time Value of Money Solution Grid lesson first.

Future Value of Single Sums

Problem 1

Find the future value of $100 in 5 years at 5%.

The solution grid:

P/YRNI/YRPVPMTFV
155100 +/-0?

The answer is:  $127.63

The calculator keystrokes:

C
  C ALL
1   P/YR
5 N
5 I/YR
1 0 0 +/− PV
0 PMT
FV

Problem 2

Find the future value of $1,800 in 3 years at 8%.

P/YRNI/YRPVPMTFV
1381,800 +/-0?

The answer is:  $2,267.48

The calculator keystrokes:

C
  C ALL
1   P/YR
3 N
8 I/YR
1 8 0 0 +/− PV
0 PMT
FV

Problem 3

Find the future value of $500 in 6 years at 9%.

The solution grid:

P/YRNI/YRPVPMTFV
169500 +/-0?

The answer is:  $838.55

The calculator keystrokes:

C
  C ALL
1   P/YR
6 N
9 I/YR
5 0 0 +/− PV
0 PMT
FV

Future Value of Annuity

Problem 1

Find the future value of a 3-year, $300 per year annuity at 6%.

The solution grid:

P/YRNI/YRPVPMTFV
1360300 +/-?

The answer is:  $955.08

The calculator keystrokes:

C
  C ALL
1   P/YR
3 N
6 I/YR
0 PV
3 0 0 +/− PMT
FV

Problem 2

Find the future value of a 15-year, $300 per year annuity at 6%.

The solution grid:

P/YRNI/YRPVPMTFV
11560300 +/-?

The answer is:  $6,982.79

The calculator keystrokes:

C
  C ALL
1   P/YR
1 5 N
6 I/YR
0 PV
3 0 0 +/− PMT
FV

Present Value

Problem

How much would you have to deposit now to have $15,000 in 8 years if interest is 7%?

The solution grid:

P/YRNI/YRPVPMTFV
187?015,000

The answer is:  $8,730.14

The calculator keystrokes:

C
  C ALL
1   P/YR
8 N
7 I/YR
0 PMT
1 5 0 0 0 FV
PV

Remember the answer is displayed as a negative value indicating that you would have a cash outflow in the present to receive a cash inflow in the future.

Present Value of Annuity

Problem

Find the present value of a 3-year, $500 annuity at 4%.

The solution grid:

P/YRNI/YRPVPMTFV
134?5000

The answer is:  $1,387.55

The calculator keystrokes:

C
  C ALL
1   P/YR
3 N
4 I/YR
5 0 0 PMT
0 FV
PV

Again, a negative value indicating a cash outflow.

Intrayear Compounding

Problem

Find the present value of a $400 payment received each six months for 3 years.
Interest is 4%, compounded semiannually.

Number of Compounding Periods (N) = Number of Years (3) × Number of Times Per Year Compounding (2)

The solution grid:

P/YRNI/YRPVPMTFV
264?4000

The answer is:  $2,240.57

The calculator keystrokes:

C
  C ALL
2   P/YR
6 N
4 I/YR
4 0 0 PMT
0 FV
PV

And again, a negative value.

Annuity Due

Problem

Find the future value of a 4-year annuity due of $400 at 6%.

As it is an annuity due, the calculator should be set for beginning-of-year cash flows.

The solution grid:

P/YRNI/YRPVPMTFV
1460400 +/-?

The answer is:  $1854.84

The calculator keystrokes:

C
  C ALL
1   P/YR
  Beg/End (Verify BEG is displayed)
4 N
6 I/YR
0 PV
4 0 0 +/− PMT
FV

Remember to set the calculator back into End mode by pressing   Beg/End until BEG clears from the calculator display.

Interest

Problem 1

If you borrow $1,000 and pay back $1,728 in three years, what annual rate of interest are you paying?

The solution grid:

P/YRNI/YRPVPMTFV
13?1,00001,728 +/-

The answer is:  20%

The calculator keystrokes:

C
  C ALL
1   P/YR
3 N
1 0 0 0 PV
0 PMT
1 7 2 8 +/− FV
I/YR

Problem 2

If you borrow $20,000 and pay back in four equal annual installments of $5,640,
what interest rate are you paying?

The solution grid:

P/YRNI/YRPVPMTFV
14?20,0005,640 +/-0

The answer is:  5%

The calculator keystrokes:

C
  C ALL
1   P/YR
4 N
2 0 0 0 0 PV
5 6 4 0 +/− PMT
0 FV
I/YR

Compounding Periods

Problem 1

You borrow $50,000 at 6% and agree to remit installments of $11,870 every year.
How many years will you do this?

The solution grid:

P/YRNI/YRPVPMTFV
1?650,00011,879 +/-0

The answer is:  5 Years

The calculator keystrokes:

C
  C ALL
1   P/YR
6 I/YR
5 0 0 0 0 PV
1 1 8 7 0 +/− PMT
0 FV
N

Problem 2

How long will it take you to triple your money at 8%?

The solution grid:

P/YRNI/YRPVPMTFV
1?81 +/-03

The answer is:  14.27 Years

The calculator keystrokes:

C
  C ALL
1   P/YR
8 I/YR
1 +/− PV
0 PMT
3 FV
N

The Rule of 72

As an aside, there is a simple calculation to estimate the number of years it would take to double an investment. The Rule of 72 states that by dividing annual interest rate into 72, the result will be an approximation of the number of years it would take for an amount to double.

For example, at 12% how long would it take to double your money?

• Rule of 72: 72 ÷ 12  =  6 years
• Using a financial calculator: 6.12 years

Solving for Payment

Problem

How much would you have to pay each year to pay off a 5%, 7-year loan of $300,000?

The solution grid:

P/YRNI/YRPVPMTFV
175300,000?0

The answer is:  $51,845.95

The calculator keystrokes:

C
  C ALL
1   P/YR
7 N
5 I/YR
3 0 0 0 0 0 PV
0 FV
PMT

The answer displays as a negative value indicating cash outflow for each payment.

This overview was developed by Dr. Sharon Garrison.
No adaptation of its content is permitted without permission.