Question

a sum of money amount to Rs 6200 in 2 years and Rs 7400 in 3 years.Find the principal and rate of interest

Answer 1

7400-6200=1200

12002(Years)=2400

P=6200-2400

P=3800

Now Rate:

I=S-P

I=7400-3800

I=3600

I=Prt

3600=38003t

t=0.31%

t=31.5789

Answer 2

The principal amount is Rs 3800 and the rate of interest is 31.57%

Given:

Given that A1 = 6200 and T1 = 2

A2 = 7400 and T2 = 3

To find:

We have to find the principle and rate of interest.

Solution:

We have to find the principle and rate of interest.

The formula is,

$A= P+PRT$

Given that,

A1=Rs. 6200 and T1=2

A2=Rs. 7400 and T2=3

Substitute the values in formula

$6200 = P+PR \times 2$

$P+2PR = 6200 --- (1)$

$7400 = P+PR \times 3$

$P+3PR = 7400 --- (2)$

By solving equations 1 and 2

$P+2PR = 6200$

$P+3PR = 7400$

We get,  

$-PR = -1200$

$PR = 1200 ----- (3)$

Substitute PR in equation 1

$P+2 \times 1200 = 6200$

$P = 6200-2400$

$P = Rs \ 3800$

Substitute P in equation 3

$(3800) \times R=1200$

$R= \frac {1200}{3800} \times 100$

$R = 31.57 \%$