Question

5. Asum of money becomes double in 10 years at a certain rate of interest. Find the rate of interest
(HINT: Let P ={x, then A = 2x, 1 = x]​

Answer 1

Answer:

If the amount doubles in 10 years, then the rate of interest would be given by the formula

FV = PV*(1+r)^n or 200 = 100(1+r)^10

Solving the equation we get, r = {2^(1/10 ) -1} = 1.07177–1 =0.0718 or 7.177% p a

Using the same formula we get 3 = (1+0.0717)^n

The n ( period ) can be calculated using the Log

n = Log 3/Log (1.07177 =0.4771/0.03010 = 15.86

It will take 15.86 Years to Triple itself  

T=log(3)÷log(1.025)=

44.4915.

44.4915 months

T is period in months ,

1.025 is (1+r), where r is the interest on ₹1 for 1 month.

PLZ MARK AS BRIANLIEST AND THX FOR THE SUPERB QUESTION

Answer 2

Step-by-step explanation:

First, you should know the equation of simple compound interest.

FV = PV(1 + i*n)

in which FV = future value, PV = present value, i = interest rate in one period, n = number of period

In this case, the period is 10 years. After 10 years, FV = 2PV

=> 2PV = PV(1 + i*n)

<=> 2 = 1+ i*n

<=> i*n = 1

<=> 10i = 1 <=> i = 0.1 = 10%

So, the interest rate here is 10%.