8.Mary invested RM3000 in two accounts, some at 12% per annum and the rest at 8 percent per annum.Her total interest for one year was RM3200.how much was invested at each rate?

9.RM 1999 was invested for a certain period. The simple interest earned was RM200. find the period if the simple interest rate offered was 10% per annum

1 answer

8. amount invested at 12% -- x
amount invested at 8% --- 3000-x

.12x + .08(3000-x) = 3200
times 100
12x + 8(3000-x) = 320000
4x = 29600
x = ??? (more than she invested!!!!)
I think you have a typo, should the interest be RM 320 ??
That way it works out nicely,
change the 3200 to 320 and repeat my calculations

9.
I = PRT
200 = 1999(.10)T
T = 200/((.1)(1999)) = 1

One year