Question

if the Simple interest for 2 yeats is Rs 650 and compound interest for 2 years at the same rate and for the same principal is Rs 715, then find the difference between simple interest and compoind interest for 3 years at the same rate and the principal?​

Answer 1

Answer:

The principal is 625 rupee

Rate is 8%

Concept: 

SI = (P × R × T)/100

CI = P[(1 + r/100)n - 1]

Here, n is the number of terms in the year.

Calculation: 

The simple interest for 2 years

⇒ (625 × 8 × 2)/100

⇒ 25 × 2 × 2

⇒ 100 rupee

Now, Compound interest for 2 years is 

⇒ 625[(1 + 8/100)2 - 1]

⇒ 625[(108/100)2 - 1]

⇒ 625[(108)2 - (100)2] × 1/10000

⇒ (208 × 8)/16

⇒ 104 rupee

Now, The difference between CI and SI is

⇒ 104 - 100

⇒ 4

∴ The difference between CI and SI is 4. 

 

The difference between CI and SI for 2 years is P(r/100)2

The  difference is 

⇒ 625(8/100)2

⇒ 625 × 4/625

⇒ 4