Problema Solution

David lends his brother some money 8% simple interest, and he lent his siter twice as much as twice the interest rate. If he received a total of $20.00 interest, then how much did he lend to each of them?

Answer provided by our tutors

let 'x' represent the amount of money lent to his brother, then '2x' represents the amount of money lent to his sister


interest = principal * rate * time

we assume time to be equal to 1


20 = 0.08x + 0.16(2x)

solving for 'x' we have x=50


50*2 = 100


David lent $50 to his brother and $100 to his sister