BANK & INSURANCE (SIMPLE AND COMPOUND INTEREST) PART 2

Total Questions: 60

41. Mohit invested Rs. 24,000 at compound interest of 40% p.a., compounded half yearly. If he received Rs. ‘2x’ after 18 months, then find the value of ‘1.5x’.

Correct Answer: (a) 31104  
Solution:

Amount = Principal × {1 + (Effective rate/100)}^(Effective terms)

Effective rate of interest = (40/2) = 20%

Effective terms = (18/12) × 2 = 3 terms, where each term consists of 6 months

So, 2x = 24000 × {1 + (20/100)}³ = 41,472

Or, 1.5x = (41472/2) × 1.5 = 31104

Hence, option a.

42. Aman earned Rs. 6,750 as interest on investing Rs. 15,000 at simple interest of 18% p.a. for ‘m’ months. If instead he had invested the same amount at compound interest of ‘m%’ p.a., compounded annually for 2 years, then find the interest that Aman would’ve earned.

Correct Answer: (b) Rs. 10,350  
Solution:ATQ: 6750 = (15000 × m × 18)/100 × 12 Or, (6750 × 100 × 12) ÷ (15000 × 18) = m Or, m = 30 So, required interest = 15000 × {1 + (30/100)}² − 15000 = Rs. 10,350 Hence, option b

43. Rakesh invested Rs. 7,500 for 4 years in scheme ‘A’ offering simple interest of 12% p.a. and re-invested the entire interest received from scheme ‘A’ in another scheme ‘B’ which offers compound interest of 10% p.a., compounded annually. Find the interest he received from scheme ‘B’ after 2 years.

Correct Answer: (e) Rs. 756
Solution:

Simple interest received from scheme ‘A’ = 7500 × 12 × 4 ÷ 100 = Rs. 3,600 = amount invested in scheme ‘B’

**Interest received from scheme ‘B’ = 3600 × {(1 + (10/100))² − 1}
= 3600 × (1.1)² − 3600
= 4356 − 3600 = Rs. 756

Hence, option e.

44. Udhay invests Rs.x in a simple interest scheme at the rate of 19% per annum for 4 years. After 4 years, he received the interest is Rs.(1872 + x/2). If Sai invests Rs.x in a compound interest scheme at the rate of 20% per annum for 2 years, then find the total amount earned by Sai after 2 years?

Correct Answer: (d) Rs.10368  
Solution:

(1872 + x/2) = x × 19 × 4/100

46800 + 12.5x = 19x

x = 7200

CA received by Sai = 7200 × (1 + 20/100)²
= Rs. 10368

45. Bala invests Rs.7200 in a simple interest scheme at the rate of R% per annum for 4 years and after 4 years, he received the total amount of Rs.11520. If Pugazh invests Rs.8000 in a compound interest scheme at the rate of R% per annum for 2 years, then find the interest received by Pugazh?

Correct Answer: (b) Rs.2580  
Solution:

11520 − 7200 = 7200 × R × 4/100

R = 15%

CI received by Pugazh = 8000 × (1 + 15/100)² − 8000
= Rs. 2580

46. Shon invested Rs.x in scheme A which offers simple interest at 15% per annum for 4 years. He also invests Rs.(x + 1000) in scheme B which offer compound interest at 10% per annum for 2 years and after 2 years he received the compound interest is Rs.714. How much is the amount of interest received by Shon in scheme A?

Correct Answer: (c) Rs.1440
Solution:

CI = P × (1 + R/100)ⁿ − P

714 = (x + 1000) × (1 + 10/100)² − (x + 1000)

714 = (x + 1000) × (21/100)

3400 = x + 1000

x = 2400

SI = P × N × R/100

= 2400 × 15 × 4/100

= Rs. 1440

47. Ramesh invests Rs.4500 in a simple interest scheme at the rate of x% per annum for 4 years. Ram invests Rs.(y + 3200) in a simple interest scheme at the rate of (x/2)% per annum for 4 years. If the interest received by Ramesh is 80% more than that of Ram, then find the value of y?

Correct Answer: (e) None of these
Solution:

SI received by Ramesh = 4500 × x × 4/100 = 180x

SI received by Ram = (y + 3200) × (x/2) × 4/100

= x(y + 3200)/50

(180x × 50)/(x(y + 3200)) = 180/100

5000 = y + 3200

y = Rs. 1800

48. The difference between the interest obtained by A in S.I and B in C.I when investing the same amount at the same interest rate for 2 years is Rs.1280. If the amount invested by A and B is Rs.8000, find the interest obtained by A.

Correct Answer: (d) Rs.8000  
Solution:

Difference = P(R/100)²

1280 = 8000 × (R/100)²

R² = 320 × 5

R = 40%

Interest obtained by A = 8000 × 40 × 2/100
= Rs. 6400

49. A sum of Rs.8000 is invested in a compound interest scheme at the rate of R% per annum for 2 years. After two years, total amount received from the scheme is Rs.10580. If the amount Rs.6400 is invested in a simple interest scheme at the rate of (R + 5)% per annum for 3 years, then find the simple interest received from the scheme?

Correct Answer: (b) Rs.3840  
Solution:

10580 = 8000 × (1 + R/100)²

10580/8000 = (1 + R/100)²

46/40 = (100 + R)/100

R = 115 − 100 = 15%

SI = 6400 × (15 + 5) × 3/100 = Rs. 3840

50. The difference between the simple and compound interest on a certain sum for 2 years at x% per annum is Rs.324 and the sum invested is Rs.14400 and then find the value of x%?

Correct Answer: (d) 15%  
Solution:

324 = (14400 × r²)/100²

324 × 100²/14400 = r²

r² = 225

r = 15%