Question

2. A sum is invested for 3 years compounded at 5%, 10% and 20 % respectively. In three years, if the sum amounts to Rs. 1506, then find the sum.

Answer 1

Answer:

Let the original amount = Rs. 100.

In the first year, it increases by 5%.

∴ the amount after 1 yr. = Rs. (100+100×

100

5

)= Rs. 105.

In the second year, it increases by 10%.

∴ the amount after 2 yr. = Rs. (105+105×

100

10

)= Rs. 115.5.

In the third year, it increases by 20%.

∴ the amount after 3 yr. = Rs. (115.5+115.5×

100

20

)= Rs. 138.6. =138.6% of Rs. 100

∴ Rs. 138.6% of the original money = Rs. 16632.

⇒ The original money = Rs.

138.6

16632

×100= Rs. 12000.