Question

A sum of money at simple interest amounts to rs 815 in 3 years and 2 rupees 854 in 4 years the sum is

Answer 1

Answer:

sum = 700 rs

Explanation

Simple Interest Equation (Principal + Interest)

A = P(1 + rt)

Where:

A = Total Accrued Amount (principal + interest)

P = Principal Amount

I = Interest Amount

r = Rate of Interest per year in decimal; r = R/100

R = Rate of Interest per year as a percent; R = r * 100

t = Time Period involved in months or years

Equation 1:

815 = P(1+r (3))

Equation 2:

854=P(1+r(4))

Solution

( (815/P )-1 )/3 = r

putting r in second equation

854 = P (1+ ( (815/P )-1 )/3 )* 4)

854 = P ( 1+ (815-p)/p)/3) * 4)

854 = P ( 1+ (815-p)/3P) * 4)

854 = P (3p + 3260 -4P ) / 3P

854 = (3260-P) / 3

2562= 3260 - P

-700 = - P

P = 700

Answer 2

Explanation:

Given

• amounts to Rs. 815 in 3 years and to A sum of money at simple interest amounts to 815 in 3 years and to 854 in 4 years.

Solution

Interest for 1 year = 854-815= Rs 39. let x be the sum and i be the interest amount for 1 year as per given info

x + 3*i = 815

x + 4*i = 854

hence i = 39. so sum x is 815-3*39=698.