With the simple interest, amount is doubled in four years . How many years it…
2023
With the simple interest, amount is doubled in four years . How many years it take to get 6 times the amount at the same rate ?
- A.
15 years
- B.
12 years
- C.
20 years
- D.
18 years
Attempted by 33 students.
Show answer & explanation
Correct answer: C
Answer: 20 years
Let the principal be P and the annual simple interest rate be r%.
Since the amount doubles in 4 years, the interest earned in 4 years is P: P * r * 4 / 100 = P, which gives r = 25%.
To become 6 times the principal the interest needed is 5P. Using P * r * t / 100 = 5P and r = 25, we get t = 500 / 25 = 20 years.
Therefore the required time is 20 years.