Simple Interest Problem Help Please

[mathox]

I don't get how to set this up
The owner of a mutual fund placed 35% of the fund's available cash in a 6% simple interest account, 25% in 8% corporate bonds, and the remainder in a money market fund that earns 7.5% simple interest. The total interest from the investments was $10,650. What was the total amount invested?

 

[stapel]

I don't get how to set this up

To learn, in general, how to set up and solve this sort of exercise, try here.

The owner of a mutual fund placed 35% of the fund's available cash in a 6% simple interest account, 25% in 8% corporate bonds, and the remainder in a money market fund that earns 7.5% simple interest. The total interest from the investments was $10,650. What was the total amount invested?

Let "x" be the total amount invested. Since the total is 100% of the total, then the amount in the money-market fund must be 100% - 35% - 25% = 40% of the total "x".

. . .amounts invested:
. . . . .at 6%: 0.35x
. . . . .at 8%: 0.25x
. . . . .at 7.5%: 0.4x

. . .interest rates:
. . . . .at 6%: 0.06
. . . . .at 8%: 0.08
. . . . .at 7.5%: 0.075

. . .interest earned:
. . . . .at 6%: 0.06(0.35x) = 0.021x
. . . . .at 8%: 0.08(0.25x) = ??
. . . . .at 7.5%: ??

Complete the table. Add the three returns on investments, and set equal to the total (given) return. Then solve the linear equation for the value of "x".

If you get stuck, please reply showing how far you have gotten. Thank you!

 

[Denis]

Hint: 35(.06) + 25(.08) + 40(.075) will give you the interest on $100