-
A sum of money at simple interest trebles itself in 15 years. It will become 5 times of itself in
-
- 40 years
- 36 years
- 30 years
- 25 years
- 40 years
Correct Option: C
Let the principal be P.
Case-I
| 2P = | |
| 100 |
| ⇒ 2P = | = | % | ||
| 15 | 3 |
Case-II
SI = 4P
| ∴ 4P = | |
| 100 |
| ⇒ T= | = 30 yaers | |
| 40 |
Second method to solve this question :
| R = | × 100% | |
| 15 |
| R = | × 100% | = | × 20% | ||
| 15 | 15 |
| R = | % | |
| 3 |
| T = | Years | |
| R |
| T = | × 100 | |
| (40 ÷ 3) |
T = 30 years.
