Answer:
7% interest = $10000
13% interest = $20000
Step-by-step explanation:
Let the amount invested at 7% interest be x.
Let the amount invested at 13% interest be y.
Thus;
x + y = 30000 - - - (eq 1)
We want to find out how much Paul needs to invest in each option to make a total 11% return on his $30,000.
Thus;
0.07x + 0.13y = 0.11(30000)
Multiply through by 100 to get rid of the decimal;
7x + 13y = 0.11(30000 × 100).
7x + 13y = 330000 - - - (eq 2)
From eq 1, x = 30000 - y
Put this for x in eq 2 to get;
7(30000 - y) + 13y = 330000
210000 - 7y + 13y = 330000
6y = 330000 - 210000
6y = 120000
y = 120000/6
y = $20000
x = 30000 - 20000
x = $10000
Thus;
Amount invested at;
7% interest = $10000
13% interest = $20000
