Annually cumulating interest can be determined by the following formula:

r represents the interest rate as a decimal, and P represents the starting amount of money.
8th payment, if you want how to get the answer I made a chart as shown in the picture
P (A and B) = P(A) * P(B)...answer is D
0.54=0.54/1=5.4/10=54/100=27/50