1.3 homework

Question

A woman has a total of $9,000 to invest. She invests part of the money in an account that pays 7% per year and the rest in an account that pays 10% per year. If the interest earned in the first year is $780 , how much did she invest in each account?

Answer 1

a + b = 9000 ------> a = 9000 - b

.07a + .1b = 780

 

.07(9000 - b) + .1b = 780

630 - .07b + .1b = 780

.03b = 150

b = 5000

 

a = 9000 - 5000 = 4000