Question

Frank invested his savings in two investment funds. The amount he invested in fund A was $2000 less than the amount he invested in fund B. Find A returned a 5% profit and fund B returned a 3% profit. How much did he invest in fund B, if the total profit from the two funds together was $1100?

Answer 1

Let x be the amount invested in fund B, then amount invested in fund A is (x -2000).

The profit from fund A is 5% of (x - 2000) and profit from fund B is 3% of x. The total profit from fund A and fund B is 1100, so

`(5)/(100)\cdot(x-2000)+(3)/(100)\cdot x=1100`

Simplify the equation for x.

`\begin{gathered} (5)/(100)\cdot(x-2000)+(3)/(100)\cdot x=1100 \\ (5)/(100)x-100+(3x)/(100)=1100 \\ (8x)/(100)=1100+100 \\ x=1200\cdot(100)/(8) \\ =15000 \end{gathered}`

So amount that Frank invested in plan B is $15000.