Problema Solution

Linda invests $25,000 for one year. Part is invested at 5%, another part at 6%, and the rest at 8%. The total income from all 3 investments is $1600. The total income from the 5% and 6% investments is equal to the income from the 8% investment. Find the amount invested at each rate.

Answer provided by our tutors

5% invest = x

6% invest = y

8% invest = z

x + y + z = 25000 (1)

0.05x + 0.06y + 0.08z = 1600 (2)

0.05x + 0.06y = 0.08z  (3)

-> from (2), (3) => 2*0.08z = 1600

=> 0.08z = 800 => z =10000

replace z = 10,000 into above equation

x + y = 15000 => x =15000 - y (1*)

0.05x + 0.06y = 800 (2*)

=> 0.05(15000-y) + 0.06y = 800

750 + 0.01y = 800

50 = 0.01y

 y = 5000

x = 15000 - 5000 = 10000

=>

5% = $10,000 ; 6% = $5,000 ; 8% = $10,000