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5.05 Comparing investment strategies

Worksheet
Compare investment strategies
1

Consider the following investment strategies:

  • Investment strategy 1: \$6420 invested at 6\% p.a. compounded monthly.

  • Investment strategy 2: \$6420 invested at 6\% p.a. compounded weekly.

  • Investment strategy 3: \$6420 invested at 6\% p.a. compounded daily.

a

Find the value of Investment 1 after 18 years

b

Assuming 52 weeks in a year, find the value of Investment 2 after 18 years.

c

Assuming there are 365 days in a year, find the value of Investment 3 after 18 years.

d

Considering a range of investment strategies that differ only by the compounding frequency, determine whether the following statements are true:

i

An investment with a higher compounding frequency will yield a higher return.

ii

An investment with a lower compounding frequency will yield a higher return.

iii

The compounding frequency does not influence the return on the investment.

2

A \$150\,000 investment earns interest at 24\% p.a., compounded monthly over 10 years.

The following table shows the balance on a \$1000 investment for a particular number of periods, n:

\text{Interest rate} \\ \text{per period}n=115n=120n=125n=130n=135
1\%3140.203300.393468.743645.683831.65
2\%9750.3410\,765.1611\,885.6113\,122.6714\,488.49
3\%29\,942.0034\,710.9940\,239.5546\,648.6654078.59
4\%90\,956.56110\,662.56134\,637.93163\,807.62199\,297.02
5\%273\,381.67348\,911.99445\,309.93568\,340.86725\,362.96

Using the compound interest table, calculate:

a

the value of this investment, correct to the nearest cent.

b

the amount of interest earned, correct to the nearest cent.

3

Beth's investment into a 12-year 4.4\% p.a. corporate bond grew to \$13190. Calculate the size of Beth's initial investment if:

a

Interest was compounded annually.

b

Interest was compounded semiannually.

c

Interest was compounded quarterly.

d

Interest was compounded monthly.

e

Interest was compounded weekly.

f

Interest was compounded daily.

4

Consider the following investment strategies over 72 months:

  • Investment strategy 1: \$2600 invested in a simple interest account at 9.6\% per month.

  • Investment strategy 2: \$2600 invested at 4.1\% p.a. compounded annually.

a

Find the value of each of the following after 72 months.

i

Investment strategy 1

ii

Investment strategy 2

b

Which option should be selected in order to maximise the return on the investment?

5

Robert plans to invest \$750 at 5.5\% p.a. compounded annually for 8 years. Jenny only has \$500 to invest, but wants to use the same strategy as Robert.

a

Find the value of each of the following after 8 years.

i

Robert’s investment

ii

Jenny’s investment

b

Suppose the interest rate, compounding frequency, and investment period are the same. Determine whether the following statements are true:

i

An investment with a lower principal value will yield a higher return.

ii

An investment with a higher principal value will yield a higher return.

iii

The principal value does not influence the return on the investment.

6

Oliver has two savings accounts that have different interest rates.

a

If Account 1 initially has \$927 and interest is earned at 1.79\% p.a. compounded weekly, find the balance in the account after 40 weeks.

b

If Account 2 initially has \$234 and interest is earned at 5.59\% p.a. compounded weekly, find the balance in the account after 40 weeks.

c

Which account has returned the most interest after 40 weeks?

7

Consider the following investment strategies that have the same annual interest rate:

  • Investment strategy 1: \$881 invested at 2.11\% p.a. compounded annually.

  • Investment strategy 2: \$397 invested at 2.11\% p.a. compounded monthly.

a

Find the value of each of the following investments after 17 years.

i

Investment strategy 1

ii

Investment strategy 2

b

Find the total interest earned from each of the following.

i

Investment strategy 1

ii

Investment strategy 2

c

Which investment strategy has grown the most after 17 years?

8

A bank offers a two-stage investment strategy to attract new savings account customers. In Stage 1, interest is earned at 5.79\% p.a. compounded monthly for the first 12 months. In Stage 2, interest is earned at 1.21\% p.a. compounded weekly for the remainder of the life of the account. Assume there are 52 weeks in a year.

a

Find the balance after 1 year in a savings account that has an initial deposit of \$977.

b

Find the balance of the same account after 2 years.

c

Throughout which stage did the account earn the most interest?

9

Sandy and Tobias are each trying to save up to buy a new computer. Sandy deposits \$750 into a savings account offering 5.9\% p.a. compounded daily. Tobias opens an identical account, but only has \$310 to deposit.

a

Find the value of Sandy’s account after 4 years.

b

Find the value of Tobias’s account after 6 years.

c

If Sandy closes her account after 4 years, and Tobias closes his account after 6 years, whose account earned the most interest over its lifetime?

10

An investment firm has \$60\,000 to invest over a period of 21 months. They are considering which of the following investment strategies to pursue:

  • Investment strategy 1: interest earned at a rate of 1.1\% p.a. compounded weekly. Assume 52 weeks in a year.

  • Investment strategy 2: interest earned at a rate of 4.2\% p.a. compounded monthly.

  • Investment strategy 3: interest earned at a rate of 7.7\% p.a. compounded annually.

a

Find the value of each of the following investments after 21 months.

i

Investment 1

ii

Investment 2

iii

Investment 3

b

Which investment strategy will return the most interest after 21 months?

11

Grace wants to invest \$1300 at 2\% p.a for 6 years. She has two investment options, compounding quarterly or compounding monthly. Calculate how much extra the investment is worth if it is compounded monthly rather than quarterly.

12

Maria has \$1000 to invest for 4 years and would like to know which investment plan to enter into out of the following three:

  • Plan 1: invest at 4.98\% p.a. interest, compounded monthly

  • Plan 2: invest at 6.44\% p.a. interest, compounded quarterly

  • Plan 3: invest at 5.70\% p.a. interest, compounded annually

Which investment plan yields the highest return?

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MS2-12-5

makes informed decisions about financial situations, including annuities and loan repayments

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