Question

A sum of money lent at simple interest amounts to Rs 3224 in 2 years and Rs 4160 in 5 years. Find the sum and the rate of interest.

Answer 1

x = sum of money to be lent
y = % rate per annum
a/q
when time= 2 years, Amount = 3224
so, 3224 = x + x*y*2/100. --------- (I)

and when time= 5 years, Amount = 4160
so, 4160 = x + x*y*5/100. --------- (II)

solving equation I and ii we get..

x =2600
and y = 12%

Answer 2

Answer:

Sum=2600

Rate of interest = 12%

Step-by-step explanation:

Let the sum be x

A=RS.3224

Time = 2years

SI¹= amount - principal

3224-x

Rate = si×100/p×t

(3224-x)×100/x×2

(3224-x)×50/x

Again,

Given,

Principal= x

Amount= 4160

Time = 5years

Si²= amount - principal

RS. 4160-x

Rate = SI×100/P×T

(4160-x)×100/x×5

(4160-x)×20/x

By question,

(3224-x)×50/x =(4160-x)×20 /x

X and X will cancel

Then,

After solving

X=2600

Means, principal=2600

SI = amount-principal

RS.(4160-2600)

RS.1560

Rate = SI×100/P×T

1560×100/2600×5

= 12%