How much was invested in each type of tree?

Question

A nursery has $55,000 of inventory in dogwood trees and red maple trees. The profit on a dogwood tree is 28% and the profit on a red maple tree is 17%. The profit for the entire stock is 20%. How much was invested in each type of tree?

Answer 1

28x + 17(55-x) = 20(55)

28-17)x = 20(55)-17(55)

11x = 3(55)

x = 3(55)/11 = 3(5 = 15

15,000 invested at 28%

40,000 invested at 17%

to get 55,000 at an average return of 20%

28-20= 8

20-17= 3

8/3 = 40/15 times as much invested at 17 as at 28% because 17 is closer to 20 than 28 is

check the answers

.28(15000)+ .17(40000) = .2(55000)

42000 + 68000 = 11000

11000=11000