Question

Aaron borrows $150 from his friend Austin. He promises to pay back the money in 4 monthly installments. Each month he wants to pay half the amount he paid the previous month. Assuming Austin does not charge any interest, how much should Aaron pay the first month to repay the money as scheduled?

Answer 1

This can be expressed by,

80 + 40 + 20 + 10 = 150

Answer 2

Assume first month's price is x

The Equation :

x+1/2x+1/4x+1/8x = 150

Multiply every term by 8 to get whole numbers

8x+4x+2x+x = 1200

15x = 1200

x = 80