Answer:
10.625%
Explanation:
The combined rate of return for two investments can be calculated using the below mentioned formula:
Combined interest=[(interest rate of first investment*first investment+interest rate of second investment*second investment)/(First investment+Second investment)]
In the given question
Combined interest=10%
Interest rate of first investment=9%
First investment=$25,000
Interest rate of second investment=?
Second investment=$40,000
10%=[(9%*25,000+Interest rate of second investment*$40,000)/(25,000+40,000)]
10%=(2250+Interest rate of second investment*$40,000)/65,000
10%*65,000=2250+Interest rate of second investment*$40,000
6500-2250=Interest rate of second investment*$40,000
4,250=Interest rate of second investment*$40,000
Interest rate of second investment=10.625%
