Question

At simple interest, a sum amounts to Rs 882 in years and amounts to Rs 1018.5
in 3.5
years
What is that rate of interest
(in percentage)?​

Answer 1

Answer:

the real rate of percentage is I dont knew

Answer 2

Given :

• A{1} = 882 , t{1} = 1 year
• A{2} = 1018.5 , t{2} = 3.5 year

Let :

• Principal = P
• rate = r

To find :

• Rate of interest

Formula used :

• I = A - P
• I = Prt

Solution :

For t= 1 year

• I{1} = A{1} - P
• I{1} = 882 - P

• I{1} = P ×r × 1
• I{1} = Pr ......... equation 1

For t = 3.5year

• I{2} = A{2} - P
• I{2} = 1018.5 - P

• I{2} = Pr × (3.5)......... equation 2

putting value of Pr from equation 1 , into equation 2

we get;

=> I{2} = I{1} × 3.5

putting value of I{1} & I{2}

we get;

=> 1018.5- P = (882-P) × 3.5

=> 1018.5 - P = 882×3.5 - 3.5P

=> 3.5P - P = 3087 - 1018.5

=> 2.5P = 2068.5

=> P = 2068.5/2.5

=> P = 827.4

Putting value of P in I{1} = 882-P

we get,

I{1} = 882 - 827.4

I{1} = 54.6

Now , putting value of P & I{1} in equation 1

we get,

=> I{1} = Pr

=> 54.6 = 827.4 × r

=> r = 54.6 / 827.4

=> r = 0.065

rate of interest in percentage = 0.065 × 100

rate of interest in percentage = 6.5%

ANSWER : rate of interest in percentage = 6.5%