Question

An investment of $5,000 is made at a simple annual interest rate of 3%. How much additional money must be invested at a simple annual interest rate of 3.9% so that the total annual interest earned is 3.5% of the total investment?

Answer 1

Answer:  Additional money is $6250.

Step-by-step explanation:

Since we have given that

Amount of investment = $5000

Rate of simple interest = 3%

Let the additional amount of investment be 'x'.

Rate of simple interest = 3.9%

Total annual interest rate on total investment = 3.5%

So, According to question, it would be

$5000\times 0.03+x\times 0.039=(5000+x)\times 0.035\\\\150+0.039x=175+0.035x\\\\0.039x-0.035x=175-150\\\\0.004x=25\\\\x=\dfrac{25}{0.004}\\\\x=\ 6250$

Hence, Additional money is $6250.