Investment Problems, How do you solve the problem below?

Question

Orlando, a financial planner, recommended that 25% of a client's investment be placed in a 4% annual simple interest tax-free account, that 40% be placed in 6% certificates of deposit, and that the remainder be placed in 9% high-risk investment. The total interest earned from the investments would be $6550. Find the total amount to be invested.

Answer 1

let x = total amount invested

interest from each investment =  amount x rate

The total interest = $6550

 

25%x(4%) + 40%x(6%) + 35%x(9%) = 6550     now solve for x

 

.25x(.04) + .40x(.06) + .35x(.09) = 6550 

 

25x(4) + 40x(6) + 35x(9) = 6550 x 100 x 100

 

100x + 240x + 315x = 65,500,000

 

655x = 65,500,000

 

x = $100,000 is total amount invested