This set of Aptitude Questions and Answers (MCQs) focuses on “Simple Interest – Set 3”.
1. A man invested x rupees for y years at 25% simple interest per annum. If the interest after 4y years is 8x, find the value of y.
a) 10
b) 8
c) 12
d) 15
View Answer
Explanation: The interest after 4y years = 4y * 25 * x / 100 = 8x
y = 8
2. A man invested 1,25,000 rupees at x% simple interest for 2.5 years. After 2.5 years the interest was 1.25 times the amount invested. Find the value of x.
a) 37
b) 48
c) 59
d) 50
View Answer
Explanation: The interest after 2.5 years = 1,25,000 * x / 100 * 2.5 = 1.25 * 1,25,000 = 1,56,250
3125x = 1,56,250, x = 156250 / 3125 = 50
X = 50
3. A man invested 1200 rupees at 4% simple interest for x years. If after x years the interest was 1.5 times the amount invested, find the value of x.
a) 34.5
b) 35.5
c) 36.5
d) 37.5
View Answer
Explanation: The interest after x years = 1200 * 4 * x / 100 = 1.5 times of 1200 = 1800
1200 * 4 * x / 100 = 1800, 48x = 1800, x = 1800 / 48 = 37.5
4. A man invested x rupees for y years at 12% simple interest. If after y years, the interest earned is 2.4 times of the amount invested, find the value of y.
a) 16
b) 17
c) 19
d) 20
View Answer
Explanation: The interest after y years = x * y * 12 / 100 = 2.4x
12y = 240, y = 240 / 12 = 20
5. A man invested 12000 at a rate of x% simple interest that earns 600 rupees interest per annum. Find the interest on 35800 rupees for 2 years at the same interest percentage.
a) 358 rupees
b) 895 rupees
c) 1790 rupees
d) 3580 rupees
View Answer
Explanation: The interest on 12000 rupees for an annum = 600 rupees
12000 * x / 100 * 1 = 600 rupees, x = 600 / 120 = 5%
The interest percentage = 5%
The interest on 35800 rupees for 2 years = 35800 * 2 * 5 / 100 = 3580 rupees.
6. A man invested 15000 rupees at 0.6% simple interest for 11.25 years. The interest earned is what percentage of the amount invested.
a) 3.25%
b) 3.75%
c) 5.25%
d) 6.75%
View Answer
Explanation: The interest earned = 15000 * 0.6 * 11.25 / 100 = 1012.5 rupees
Percentage earning = 1012.5 / 15000 * 100 = 6.75%
7. A man invested 4560 rupees at 46% simple interest for x years. If the amount tripled itself in x years, find the value of x.
a) 4.14 years
b) 4.28 years
c) 4.34 years
d) 4.77 years
View Answer
Explanation: The amount tripled itself in 3 years, this implies that the interest on the amount for x years is twice the amount.
The interest in x years = 4560 * 46 * x / 100 = 2 * 4560
X = 4.34 years
8. A man invested a sum of 80000 rupees for 21 years at x% simple interest. If the interest for 21 years is 375% of the amount invested, find the value of x.
a) 13.35
b) 15.57
c) 17.85
d) 18.57
View Answer
Explanation: The interest for 21 years = 3.75 times the amount invested = 3.75 * 80000 = 300000
The interest = 80000 * 21 * x / 100 = 300000, x = 17.85%
X = 17.85
9. A man invested a sum of x rupees for y months at a rate of 12% per month simple interest. Find the time in which the sum will triple itself.
a) 16.66 months
b) 1.5 years
c) 24 months
d) 1.8 years
View Answer
Explanation: The interest earned in y months = x * y * 12 / 100 = 2x
Y * 12 / 100 = 2, y = 200 / 12 = 16.66 months
10. A man invested 24% of his income at a rate of 0.05% simple interest of the amount he invested for 45 years. If the man earns 120000 rupees, find the interest after 45 years, as a percentage of the amount he invested.
a) 630%
b) 638%
c) 640%
d) 648
View Answer
Explanation: The amount he invested = 24% of his earnings = 24% of 25000 = 28,800 rupees.
The interest rate = 0.05% of the amount he invested = 0.05% of 28,800 = 14.4%
The interest after 45 years = 28,800 * 14.4 * 45 / 100 = 1,86,624 rupees
The interest as a percentage of the amount he invested = 1,86,624 / 28,800 * 100 = 648%
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