Original practice · fully worked
Original variant: deposit required under a two-stage annual crediting schedule
A saver deposits the same amount at times 0, 1, 2, 3, 4, and 5. The account earns 4% in each of the first three years and 3% in each of the next two years. Immediately after the time-5 deposit the balance must be 50,000. Calculate each deposit.
- A
6,885.92 - B
7,268.47 - C
7,651.02 - D
8,033.57 - E
8,416.13
Answer and calculation
Accumulating each of the six deposits through the appropriate 4% and 3% periods gives a combined factor of 6.535074. Dividing 50,000 by that factor gives deposit 7,651.02, choice C.
Setup
Setup
Use time 5 as the comparison date and retain the exact rate regime traversed by each deposit.
F5=D[(1.04)3+(1.04)2+1.04](1.03)2+D[(1.03)2+1.03+1] Model
Model
Factor out the common deposit and set the accumulated value equal to the target balance.
50000=D([(1.04)3+(1.04)2+1.04](1.03)2+(1.03)2+1.03+1) Compute
Compute
The accumulation coefficient is 6.535074, so D = 7651.02.
D=6.535073657650000=7651.023174 Answer
Answer
Each deposit is 7,651.02, selecting choice C.
D≈7651.02(C)