1. Find compound interest on Rs. 7,300 at the rate of 4% per annum for 2 year s, compounded annually?
A. Rs. 612
B. Rs. 300
C. Rs. 600
D. Rs. 630
Answer - Option A
Explanation -
A = 7500 * [latex]{(1 +\frac {4} {100})}^{2}[/latex] = 812
i.e, CI = 8112 – 7500 = 612
2. In how many years, a sum will be thrice of it at simple interest @10% per annum ?
A. 15 years
B. 20 years
C. 30 years
D. 40 years
Answer - Option B
Explanation -
According to the question sum becomes thrice.
If Rs. P is invested, it becomes 3P
i.e, Interest earned = 2P
2P = [latex]\frac {P * 10 * T} {100}[/latex]
T = 20years
3. A sum of money amounts to Rs. 9680 in 2 years and Rs. 10648 in 3 years. The rate of interest per annum on compounded basis is
A. 5%
B. 10%
C. 15%
D. 20%
Answer - Option B
Explanation -
According to the question
9680 = P [latex]({1 + \frac {r} {100}})^{2}[/latex]
10648 = P [latex]({1 + \frac {r} {100}})^{3}[/latex] = P [latex]\frac {10648} {9680}[/latex] = P [latex]1 + \frac {r} {100}[/latex]
1.1 = 1 + [latex]\frac {r} {100}[/latex]
r = 10% P.a
4. A man buys a TV by making cash down payment of Rs. 4945 and agrees to pay two more yearly installments of equivalent amounts at the end of first year and second year. If the rate of interest is 7 [latex]\frac {1} {2}[/latex]% per annum, compounded annually, the cash value of the TV (in Rs.) is nearest to
A. 12840
B. 13804
C. 13824
D. 14835
Answer - Option C
Explanation -
Let c be the cost of T.V.
c = 4945 [latex]( 1 + \frac {1} {1.075}+ \frac {1} {{1.075}^{2}})[/latex]
= 4945 + 4600 + 4279 = 13824
5. A sum of Rs.5000 amounts to Rs 8640 at compound interest in a ain times, then the same sum
amounts to what in one-third of the time?
A. Rs 5886
B. Rs 6000
C. Rs 6214
D. Rs 7000
Answer - Option B
Explanation -
8640 = 5000 [latex]({1 + \frac {r} {100}})^{T}[/latex] .......(i)
k = 5000 [latex]({1 + \frac {r} {100}})^{\frac{T}{3}}[/latex]
cubing both sides
[latex]{k}^{3}[/latex] = [latex]{5000}^{3}[/latex] [latex]({1 + \frac {r} {100}})^{T}[/latex] .......(ii)
Divide (1) and (2)
[latex]{k}^{3}[/latex] = [latex]{5000}^{2}[/latex] * 8640
k = 6000
6. A loan of Rs.62496 is to be paid back in three equal annual installments. I f the inter est is compounded annual ly at 12 [latex]\frac {1} {2}[/latex] %, t hen each installments will be of (in Rs.)
A. 26736
B. 26244
C. 25736
D. 24244
Answer - Option B
Explanation -
Let equal instruments be of Ps. x
x([latex]{1.125})^{2} + 1.125 + 1[/latex] = 62496 [latex]({1.125})^{3}[/latex]
i.e, x = 26244
7. Two equal sum are lent out at 6 % and 5% simple interest per annum respectively at the same time. The first is recovered 24 years earlier than the second one and the amount received in each case was Rs. 28800. Each sum (in Rs.) was
A. 18000
B. 20000
C. 20500
D. 2200
Answer - Option A
Explanation -
Let each sum be Rs. x
According to the question
[latex]\frac {x * 6* (t - 24)} {100}[/latex] = [latex]\frac {2 * 5 * t} {100}[/latex]
Also, x + [latex]\frac {x * 5 * f} {100}[/latex] = 28800
x = 18,000
8. A computer is available for Rs. 22750 cash payment or for Rs. 6200 cash down payment and three equal annual installments of Rs. x. If the interest charged is 10% per annum. Compounded annually, the value of x is
A. 5517
B. 5578
C. 6565
D. 6655
Answer - Option D
Explanation -
(22750 – 6200) [latex] {(1.2)}^{3}[/latex] = x [latex] {(1.1)}^{2}[/latex] + (1.1) + 1
x = 6655
9. A sum of money at simple interest amounts to Rs.13800 in 3 years . If rate of interest is increased by 30%,the same sum amounts to Rs.14340 in the same time. The rate of interest per annum is
Answer - Option C
Explanation -
[latex]\frac {P * (1.3r) * 3} {100}[/latex] - [latex]\frac {P * r * 3} {100}[/latex] = 540
Pr = 60000
Also, P + [latex]\frac {P * r * 3} {100}[/latex] = 13,800
r = 5%
10. A person borrowed some money on compound interest and returned it in three years in equal annual installments. If the rate of interest in 15% per annum and the annual installment is Rs.48668, then the sum borrowed was (in Rs )
A. 101020
B. 111050
C. 111120
D. 146004
Answer - Option C
Explanation -
Let money borrowed be Rs. x
According to the question
48668 ([latex]{1.5})^{2} + 1.15 + 1[/latex] = x [latex]({1.15})^{3}[/latex]
x = 111120
11. A sum of Rs. x at simple interest amounts to Rs. 14160 i n 3 year s. If the rate of interest is increased by 25 % the same sum amounts to Rs.14700 in the same time. The value of x is
A. 120000
B. 12400
C. 13000
D. 13400
Answer - Option A
Explanation -
According to the question
[latex]x + \frac {x * r* 3} {100}[/latex] = 14160 ....(1)
[latex]x + \frac {x *(r + \frac{r}{4}) * x3} {100}[/latex] = 14700 ....(2)
solving (1) & (2)
i.e, x =12000.
12. A certain sum of many is borrowed at compound interest for 3 year s at 5% per annum. The interest for the third year is greater than that of second year by Rs.642.60. t he sum (in Rs.) borrowed is
A. 24480
B. 185400
C. 244800
D. 368400
Answer - Option C
Explanation -
I = Interest
[latex] {n}_{1st year}[/latex] = [latex]\frac {P} {20}[/latex]
[latex] {n}_{2nd year}[/latex] = [latex]\frac {P} {20} + \frac {P} {400} +\frac {21P} {400}[/latex]
[latex] {n}_{3nd year}[/latex] = [latex]\frac {P} {20} + \frac {P} {400} + \frac {21P} {20 * 400}[/latex]
[latex]\frac {4P} {8000}[/latex] = 642.6
i.e, P = 244800
13. A sum of Rs. 129780 is be paid back in three equal half yearly installments. If the interest is compounded half yearly at the rate of 3 [latex]\frac {1} {3}[/latex]% per annum, then each installment is of Rs.
A. 44690
B. 45960
C. 46080
D. 49152
Answer - Option D
Explanation -
Let each installment be Rs. x
[latex](129780) {(1.0665)}^{3}[/latex]
x ([latex] {1.0665}^{2} + (1.0665) + 1[/latex])
x = 49152
14. A loan of Rs. 26480 is to be paid back in three equal yearly installment s. If the interest is compounded yearly at 10% per annum, then each installment is of Rs.
A. 11548
B. 10864
C. 10648
D. 8827
Answer - Option C
Explanation -
(26480) [latex] {1.1}^{3}[/latex]
([latex] {1.1}^{2} + (1.1) + 1[/latex])x
x = 10648
15. A sum of Rs.78060 is divided between A and B, so that the amount of A after 3 [latex]\frac {1} {2}[/latex] years is equal to the amount of B after 4 [latex]\frac {1} {2}[/latex] year, the interest is compounded half yearly at 8% per annum. The share of B in the given sum is (in Rs.)
A. 40560
B. 38560
C. 37800
D. 37500
Answer - Option D
Explanation -
Let sum with B = x
i.e, sum with A = (78060 – x)
According to the question
[latex](1 + \frac {4} {100})^{9}[/latex] = (78060 - X) [latex](1 + \frac {4} {100})^{7}[/latex]
x[latex](1 + \frac {4} {100})^{2}[/latex] = 78060 - x
x = 37500