A person invests an amount at 5% rate of interest in first year and at

1.	A person invests an amount at 5% rate of interest in first year and at 10% in second year. He receives an amount of Rs. 1155 at the end of two years. Calculate principal amount invested.1. Rs. 23002. Rs. 18003. Rs. 10004. Rs. 1200
Answer» Correct Answer - Option 3 : Rs. 1000 Given: A= Rs. 1155 R = 5% and 10% N = 2 years Formula used: I = PRN / 100 Where P = Principal amount, R = Rate of interest in %, N = Number of years, I = Interest earned A = P + I Where A = Amount received Calculation: A = P + I ⇒ A = P + (PRN / 100) ⇒ A = P (1 + RN / 100) ⇒ A = P (1 + (5 × 1 / 100)) × (1 + (10 × 1 / 100)) [∵ Interest was 5% and 10% in 1^st and 2^nd year] ⇒ 1155 = P × (21 / 20) × (11 / 10) ⇒ P = (1155 × 20 × 10) / (21 × 11) ⇒ P = 5 × 20 × 10 ⇒ P = Rs. 1000 ∴ Principal amount invested Rs. 1000. Short Trick If we take 100 as the principle. After the first year the principle increased to 105. And after second year, the amount increased to 115.5. If he received 1155 as amount. Then, 1 unit is 10 Then, 100 unit is 1000.

A person invests an amount at 5% rate of interest in first year and at 10% in second year. He receives an amount of Rs. 1155 at the end of two years. Calculate principal amount invested.1. Rs. 23002. Rs. 18003. Rs. 10004. Rs. 1200

Answer» Correct Answer - Option 3 : Rs. 1000

Given:

A= Rs. 1155

R = 5% and 10%

N = 2 years

Formula used:

I = PRN / 100

Where P = Principal amount, R = Rate of interest in %, N = Number of years, I = Interest earned

A = P + I

Where A = Amount received

Calculation:

A = P + I

⇒ A = P + (PRN / 100)

⇒ A = P (1 + RN / 100)

⇒ A = P (1 + (5 × 1 / 100)) × (1 + (10 × 1 / 100)) [∵ Interest was 5% and 10% in 1^st and 2^nd year]

⇒ 1155 = P × (21 / 20) × (11 / 10)

⇒ P = (1155 × 20 × 10) / (21 × 11)

⇒ P = 5 × 20 × 10

⇒ P = Rs. 1000

∴ Principal amount invested Rs. 1000.

If we take 100 as the principle.

After the first year the principle increased to 105.

And after second year, the amount increased to 115.5.

If he received 1155 as amount.

Then, 1 unit is 10

Then, 100 unit is 1000.