.035 is the answer to your question
Answer:
He must invest R297 521 today.
Step-by-step explanation:
The compound interest formula is given by:

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
Banabas must pay his ex-wife an amount of R350 000 in two years’ time.
This means that 
Interest rate of 8.15% per annum compounded monthly:
This means that
.
Amount he must invest today:
This is P. So




He must invest R297 521 today.
297:5.5
divide 5.5 by both sides which
5.5 divided by 5.5 is 1 and 297 divided by 5.5 is 54
1:54
the unit rate:
54 minutes per word or 54/1