Simple Interest problems
- 1. Two equal amounts of money are deposited in two banks, each at 15% per annum for 3 1/ 2 years and 5 years. If the difference between their interests is Rs. 144, each sum is?
Options- A. Rs. 460
- B. Rs. 500
- C. Rs. 640
- D. Rs. 720 Discuss
Correct Answer: Rs. 640
Explanation:
Let each sum be Rs. P.
Then, [(P x 15 x 5) / 100] - [(P x 15 x 7) / 100] x 2 = 144
? 3P/4 -21P/40 = 144
? 9P/40 = 144
? P = (144 x 40) / 9 =Rs. 640
- 2. If the rate of interest rises from 6 1/2 to 8% a man's annual income increases by Rs. 4050. Find the capital.
Options- A. Rs . 270000
- B. Rs . 370000
- C. Rs . 300000
- D. None of these Discuss
Correct Answer: Rs . 270000
Explanation:
Due to the rise in the rate of interest, annual income increases by Rs . (8 - 61/ 2) = Rs , 11/ 2
Thus, the required capital = (100 x 2 x 4050) / 3 = Rs. 270000
- 3. The simple interest on a sum of money will be Rs. 600 after 10 years. If the principal is trebled after 5 years the total interest at the end of 10 years will be?
Options- A. Rs. 600
- B. Rs. 900
- C. Rs. 1200
- D. Data inadequate Discuss
Correct Answer: Rs. 1200
Explanation:
Let the sum be Rs. P, SI = Rs. 600, Time = 10 years
? Rate (600 x 100) / (P x 10)%
S.I for first 5 years = Rs. (P x 5 x 6000)/(1000 x P) = Rs. 300
S.I for last 5 years = Rs. (3P x 5 x 6000)/(100 x P) = Rs. 900
Hence, total interest at the end of 10 years = 300 + 900 = Rs. 1200.
- 4. A sum of Rs. 2540 is lent out into two parts. One at 12% and another one at 12 1/ 2 %. If the total annual income is Rs. 311.60, the money lent at 12% is?
Options- A. Rs. 1180
- B. Rs. 1360
- C. Rs. 1240
- D. Rs. 1340 Discuss
Correct Answer: Rs. 1180
Explanation:
Let money lent at 12% Rs. P
Then, money lent at 121/2% = Rs. (2540 - P )
? (P x 12 x 1)/100 + {(2540 - P) x 25/2 x 1}/100 = 311.60
? 3P/25 + 2540 - P/8 = 311.60
? 24P + 25(2540 - P) = 200 x 311.60
? P = 63500 - 62320 = 1180
- 5. A man lends Rs. 10000 in four parts. If he gets 8% on Rs. 2000, 7 1/ 2% on Rs . 4000 and 8 1/ 2% on Rs. 1400, What per cent must he get for the remainder if the average interest is 8.13%?
Options- A. 7%
- B. 9%
- C. 91/4%
- D. 101/2 % Discuss
Correct Answer: 9%
Explanation:
? [ (2000 x 8 x 1) /100] + [ (4000 x 15/2 x 1)/100] + [(1400 x 17/2 x 1) / 100] + [(2600 x R x 1)/100] = (10000 x 8.13 x 1) / 100
? 160 + 300 + 119 + 26R = 813
? 26R = 234
? R = 9%
- 6. If the simple interest for 5 yr be equal to 40% of the principle, it will be equal to the principle after?
Options- A. 12 yr 3 months
- B. 12 yr 6 months
- C. 12 yr 4 months
- D. 12 yr 9 months Discuss
Correct Answer: 12 yr 6 months
Explanation:
If interest is 40% of the principal then time = 5 years.
So, when interest would be equal to 100% of the principal time would be
= (100/40) x 5 years = 12.5 years
= 12 yr 6 months
- 7. What sum of money lent out at simple interest will amount to ? 3400 in 3 yr at 1% per month?
Options- A. ? 2400
- B. ? 1800
- C. ? 1600
- D. ? 2500 Discuss
Correct Answer: ? 2500
Explanation:
A = ? 3400 T = 3 yr , R = 1% per month = 12 % per annum Let the principle be ? P.
SI = (PTR/100) = (P x 3 x 12)/100 = ? 36P/100
A = (P + SI) = P + 36P/100 = ? 136P/100
? 136P/100 = 3400
? P = (3400 x 100)/136 = 2500
? Sum = ? 2500
- 8. Simple interest on ? 1680 for 4 yr at 7 1/ 2 per annum is equal to the simple interest on ? 1200 at 7% per annum for a certain period of time. Time period of time is?
Options- A. 7 yr
- B. 6 yr
- C. 51/3 yr
- D. 71/4 yr Discuss
Correct Answer: 6 yr
Explanation:
Let the required period of time be T yr.
Then, (1680 x 4 x 15) /100 = (1200 x T x 7)/100
T = (1680 x 2 x 12)/(1200 x 7)
= 6 yr
Hence, the required time period is 6 yr.
- 9. If a certain sum of money becomes double at simple interest in 12 yr. What would be the rate of interest per annum?
Options- A. 81/3%
- B. 10%
- C. 12%
- D. 14% Discuss
Correct Answer: 81/3%
Explanation:
Let the amount be P, then amount after 12 yr = 2 P
SI = 2P - P = P
SI = (P x R x T)/ 100
P = (P x R x 12)/ 100
? R = 100/12 = 81/3%
- 10. A sum of ? 4000 is lent out in two parts, one at 8% simple interest and other at 10% simple interest. If the annual interest is ? 352, the sum lent at 8% is
Options- A. ? 1600
- B. ? 2400
- C. ? 1800
- D. ? 2800 Discuss
Correct Answer: ? 2400
Explanation:
Let the money interest at 8% interest be ? P .
Then, the money interest at 10% interest = ?(4000 - P)
According to the question,
(P x 8 x 1)/100 + [(4000 - P) x 10 x 1]/100 = 352
? 8P + 40000 - 10P = 35200
? 40000 - 35200 = 2P
? P = 4800/2 = ? 2400
More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.