Q.if a certain sum of money invested at a certain rate of compound interest doubles in 5 years. in how many years will it becomes 4 times
A) 5
B) 11
C) 10
D) 8
Related Questions
Q.
Find the compound interest on Rs.1600 at 12½% per annum foe 2 years.
A) 240
B) 250
C) 320
D) 425
Q.
The compound interest on a Rs.20480 at 20% per annum for 2 years 73 days
A) 9000
B) 10190
C) 8452
D) 9600
Q.
The differnce between the compound interest and simple interest on a certain sum of money at 10% per annum for 2 years is Rs.46.Find the sum
A) 5000
B) 4500
C) 4600
D) 4000
Today's Challenging Question
Q.
Ajay & Bimal can do a price of work in 10 days, Bimal & Chetan can do in 15 days and Chetan and Ajay in 20 days. They work together for 6 days and then Ajay leaves and now Bimal & Chetan work together for 4 more days. If Bimal leaves, how long will Chetan take to finish the work?
A) 12 days
B) 10 days
C) 16 days
D) none 3 members solved
Solve Challenging question
Q.
Ajay & Bimal can do a price of work in 10 days, Bimal & Chetan can do in 15 days and Chetan and Ajay in 20 days. They work together for 6 days and then Ajay leaves and now Bimal & Chetan work together for 4 more days. If Bimal leaves, how long will Chetan take to finish the work?
A) 12 days
B) 10 days
C) 16 days
D) none
Correct Answer: 10
Solution:
let the principal amount=P, Rate of Interest=R% and Time=5 years
Then amount= \(2P=P(1+\frac{R}{100})^5\)
let for n years the amount will be 4 times then
\(4P=P(1+\frac{R}{100})^n\)
From the above 2 equations we get \(2^\frac{n}{5}=2^2\) by solving we will get n=10
so answer is 10 years