Question

Helene invested a total of $1,750 in two simple-interest bank accounts. one account paid 4% annual interest; the other paid 5% annual interest. the total amount of interest she earned after 1 year was $79. find the amount invested in each account.

Answer 1

Total investment by Helena was $1750
Suppose, in one bank she invested $x,
then in the other bank, she invested $(1750-x)
Annual interest paid by the first bank was 4% of x
i.e; 4x/100
Similarly, the second bank paid 5% of (1750-x)
i.e; 5(1750-x)/100
Total Interest she earned was $79
So we can say,
4x/100 + 5(1750-x)/100 = 79
or, 4x-5x+8750 =7900
or, -x = -850
so x= 850
1750-x =1750-850 = 900
So, in one bank she invested $850, and in the other bank, she invested $900.