Aptitude - Compound Interest - Discussion

Thanks people. It helped a lot!

Thanks, friends. It helped a lot!

Why we add 30000 and 4347, can anyone please explain it?

To find the period in years, we need to use the formula for compound interest:

A = P(1 + r/n)^(nt).

Where:
A = Final amount.
P = Principal amount (Rs. 30,000).
r = Annual interest rate (7% or 0.07).
n = Number of times the interest is compounded per year (Generally compounded annually, so n=1)
t = time in years.

Given:
Compound interest (CI) = Rs. 4347.
Principal amount (P) = Rs. 30,000.
Rate of interest (r) = 7% or 0.07.
Number of times compounded per year (n) = 1.

We have to find time, t.

First, let's calculate the final amount using the formula:

A = P(1 + r/n)^(nt).
A = 30000(1 + 0.07/1)^(1*t).
4347=30000(1.07)^t.

Now, we solve for t by converting it into a logarithmic form by taking log on both sides.

log4347/log30000 = log(1.07)^t.
log((4347/30000) = log((1.07)^t).
t = log((4347/30000))/(log(107)).
t = 3 years.

What is the shortcut method for calculating the square root of 11449?

Can any one please help how it has come (107/100)^2

Yaa, its because (107)^2 = 11449 and (100)^2 = 10000.

What is 107/100 ?

Amount=30000+4347 = 34347
amount=p(1+R/100)^n
34347=30000(1+7/100)^n
34347=30000(107/100)^n
34347/30000=(107/100)^n
11429/10000=(107/100)^n.
hence
(107/100)^2=11429/10000.

4347=30,000(1+7/100)^n why not?
and 30,000+4347=34,347 why?
plz any one explian me.