Question

simple interest on a certain sum of money for 5 years at 5% per annum is half the compound interest on rupees 3000 for 2 years at 10% per annum the sum placed on simple interest is​

Answer 1

Step-by-step explanation:

compound interest :- 3000×21.55/100 = 646.5

that is 3646.5

now simple interest :- 3000×2×10/100 =600

that is 3600

Answer 2

Answer:

820 rs

Step-by-step explanation:

Given:

Principal = 2400

Time = 2 years

Rate of Interest = 3% on SI and 5% on CI

Formula:

SI = PRT/100

CI = P(1 + R/100)n - P

Here, P = Principal, R = Rate, CI = Compound interest, n and t = Time

Calculations:

CI = 2400 × [1 + (5/100)]2 – 2400

⇒ 2400 (21/20)(21/20) – 2400

⇒ 6 × 21 × 21 – 2400

⇒ 2646 – 2400

⇒246

SI = 246/2 = 123

⇒ Sum = 123 × 100/5 × 3

⇒ Rs. 820

∴ Sum placed on simple interest is Rs. 820

Let the principal be x.

⇒ CI/2 = SI

⇒ (2400 × 10.25/100)/2 = x × 5 × 3/100

⇒ x = Rs. 820

∴ Sum placed on simple interest is Rs. 820