At what rate of compound interest a sum of money triples in two years then in how many years it will become 27 times?

Let the sum be Rs p, rate be r% per annum.
`3p = p(1+r/100)^(3) rArr (1+r/100)=3^(1//3)`
Now, `9p = p(1+r/100)^(n) rArr (1+r/100)^(n)=9`
`3^(n/3) = 3^(2) rArr n/3 rArr n=6`.
`therefore` In 6 years, the sum becomes 9 times itself.

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

No worries! We‘ve got your back. Try BYJU‘S free classes today!

No worries! We‘ve got your back. Try BYJU‘S free classes today!

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Solution

The correct option is A24 yearsP(1+R100)12=3P⇒(1+R100)15=3PP = 3……(i) Let P(1+R100)n=9P⇒(1+R100)n=9⇒(1+R100)n =32⇒(1+R100)n = {(1+R100)12}2 {using(i)}⇒(1+R100)n = (1+R100)24⇒ n = 24Thus, the required time = 24 years.

Textbooks

Question Papers

Home

How many years will a sum become 27 times when it trebles itself in 2 years at CI?

So the answer is 6 years.

At what rate per cent will the compound interest does a sum of money become 27 times in 3 years?

The rate of interest per annum is 200 %.

What rate compounded annually will triple a sum in 4 years?

R=12. 5%

What is the rate of interest if a sum of money triples itself in 16 years?

⇒R=162×100=12. 5%