Question

A certain sum of money amounts to rs. 2,613 in 6 years at 5% per annum si. in how many years will it amount to rs. 3,015 at the same rate?\

Answer 1

look
interest amt.=2613
n=6
r=5℅
$si = \frac{pnr}{100}$
2613=p×6×5/100
p=261300/30
p=8710
now
si=3015
n=?
p=8710
r=5

3015=8710×n×5/100
n=301500/43550
n=6.9320 year....

i hope You understand

Answer 2

Let Principal amount be 'P'.

Let N is no. of years of deposit

Let R is rate of interest

We know that, Simple Interest SI = PNR/100

Also, Final amount after maturity (FA) = Principal amount (P) + Simple Interest SI

FA - P = SI

It is given that a principal amount becomes Rs.2613 in 6 years at 5%

Therefore,

2613 - P = P * 6 * 5 /100

P = 2613 - (3P/100)

10P = 26130 - 3P

13P = 26130

Therefore, Principal amount P = Rs.2010

Similarly, when FA = Rs.3015 at 5%

3015-2010 = 2010*N*5/100

1005 = (201 / 2) * N

N = 10

So, in 10 years, the sum of money (Rs.2010) will become Rs.3015 at 5% rate.