Question

Anita’s sister invested all of $6000 at 4% and at 6%. If the annual return on the 6% investment is $15 more than the annual return on the 4% investment, find how much is invested at the latter rate.

Answer 1

Equations:
x (4%)
y (6%)
x+y=6000
0.06y=0.04x+15
The answer would be 2550, so $2550.

Answer 2

$3,450

Explanation:

The amount invested in the two portfolios sums up to $6,000. Given that the annual return on the 6% investment is $15 more than the annual return on the 4% investment, then if the annual return on the 4% investment is I, the returns on the 6% investment will be

= I + 15 (in $)

the return on investment may be computed using the simple interest formula

I = PRT/100

Where I is the return, P is the amount invested, R is the rate of returns and T is time in years.

let the amount invested in the 4% investment be D, then the amount invested in the other will be

= 6000 - D

Considering the two investments

I = D * 4 * 1/100

100I = 4D

D = 25I

I + 15 = (6000 - D) * 6 * 1/100

100I + 1500 = 36000 - 6D

100I + 6D = 34500

4D + 6D = 34500

10D = 34500

D = $3,450