Investment Savings.

Question

Teresa invested her savings in two investment funds. The amount she invested in Fund A was twice as much as the amount she invested in Fund B. Fund A returned a 5% profit and Fund B returned a 8%
profit. How much did she invest in Fund B, if the total profit from the two funds together was $2160?

Answer 1

Here's the information we are given:

 

FundA = 2* FundB

FundA return is FundA * .05

FundB return is FundB * .08

 

We are looking for the total profit, which  is the sum of both returns.

 

Profit = (FundA * .05) + (FundB * .08)

 

We can substitute 2 * FundB for FundA and solve for FundB:

 

Profit = ((FundB * 2) * .05) + (FundB * .08)

 

Plug in numbers to make an equation:

2160 = FundB * 2 * .05 + FundB* .08

 

Collect terms:

$2160 = FundB(2*.05 + .08)

$2160 = FundB(.18)

 

Divide to isolate FundB:

$2160/.18 = FundB

 

FundB = $12000

 

 

 

 

 

Answer 2

Best way to solve these is to list what we know:

 

x = amount invest in Fund B

2x = amount invested in Fund A

 

Profit of A = 5% on investment 2x
Profit of B = 8% on investment x

Profit of A + Profit of B = $2160

 

So:

.05(2x) + .08(x) = 2160

.1x + .08x = 2160

.18x = 2160

x = 12000

 

Proof: .08(12000) = $960

.05(24000) = $1200

1200 + 960 = $2160 which checks.