Question
A sum of money becomes 3 times of itself in 4 years when invested on simple interest. In how many years will it become 9 times of itself if the rate of interest remains the same?
Solution
Let the sum invested be Rs. 'p' and rate of interest be 'R%' p.a.
Simple interest = Principal x rate x time Γ· 100
When sum of money becomes 3 times of itself, simple interest earned = 3p - p = Rs. 2p
So, 2p = p x R x 4 Γ· 100
Or, 'R' = (200/4)
Now, when sum of money becomes 9 times of itself, simple interest earned = 9p - p = Rs. 8p
Let required time be 'T' years.
So, 8p = p x (200/4) x T Γ· 100
Or, 8 = T/2
Or, 'T' = 16
- A certain sum when invested at compound interest of 5% p.a. amounts to Rs. 4410.25 in 2 years. Find the amount received when the same sum is invested at 15...
- βWhen Rs. (a + 800) is invested at 30% p.a. simple interest for 5 years it gives an interest of Rs. (4a + 900). Find the value of βaβ.
- The simple interest on a sum of money for 4 years at 8% per annum is βΉ1,280. What will be the compound interest on the same sum at the same rate of interes...
- Neha borrowed some money from Priya at 6% p.a. simple interest for 6 years. After 6 years, she returned the amount to Priya and again borrowed 3/5th of the...
- A sum when invested at simple interest of 5% p.a. amounts to Rs. 18,000 after 4 years. If the same sum was invested at simple interest of 12% p.a. for 3 ye...
- David takes a loan of Rs. 20000 from his friend Alex, which he is to return at 10% p.a. simple interest after 5 years. Alex takes a loan from George, which...
- Shivam invested 24000 at 15% p.a. simple interest for βxβ months. If at the end of βxβ months, he received a total amount of Rs.26400. What is the value of...
- 1000 rupees is invested in a scheme p.a. simple interest. Another amount (1000 – x) is invested in scheme B at 2R% p.a. simple interest. After 5 year...
- Rs. 15,000 becomes Rs. 21,900 after 6 years on simple interest. What is the rate of interest per annum?
- The ratio of investment of A and B is 6:7 respectively. If the rate of interest for both A and B is 12% p.a and time duration for A and B is 5 years and 4 ...