# S.I. & C.I. (10)

1. A four years NSC certificate was purchased for Rs. 500 with Rs. 1000 being the maturity value. Find the rate of S.I.
1. 24%
2. 22%
3. 16%
4. 25%

Answer & Explanation

Answer:- 4

Explanation :-

P = Rs. 500    SI = Rs.500    T = 4
R = (SI * 100)/PT = (500*100)/(500*4)
R = 25%

2. If simple interest on a certain sum of money for 8 years at 4% per annum is same as the simple interest on Rs. 560 for 8 years at the rate of 12% per annum then the sum of money is
1. Rs.1820
2. Rs.1040
3. Rs.1120
4. Rs.1680

Answer & Explanation

Answer:- 4

Explanation :-

Lets suppose the sum of money be x.
Therefore, [(x*4*8)/100] = [(560*12*8)/100]
=> x*4*560*12*8
=>x = Rs. 1680

3. If a sum of money trebles itself in 40 years,what is the rate of interest?
1. 5%
2. 6%
3. 4%
4. None of these

Answer & Explanation

Answer:- 1

Explanation :-

Let the sum of money be x and rate of interest be R%
SI = 3x – x = 2x
2x = (x*R*40)/100
R = (2x * 10)/(x * 4)
R = 5%

4. Ruby invested an amount of Rs. 5,800 for 2 years. At what rate of compound interest will she get an amount of Rs. 6394.5 at the end of two years ?
1. 5 p.c.p.a.
2. 4 p.c.p.a.
3. 6 p.c.p.a.
4. 8 p.c.p.a.
5. None of these

Answer & Explanation

Answer:- 1

Explanation :-

Compound Interest  in 2 years = 6394.5 – 5800 = 594.5
A = P (1+R/100)^T
6394.5 = 5800(1+R/100)^2
(63945/58000) = (1+R/100)^2
(12789/11600)= (1+R/100)^2
R= 5%

5. A lent Rs 5000 to B for 2 years and Rs 3000 to C for 4 years on simple interest at the same rate of interest and received Rs 2200 in all from both of them as interest. The rate of interest is
1. 5%
2. 7%
3. 8%
4. 9%
5. None of these

Answer & Explanation

Answer :- 5

Explanation :-

Let the rate be R% p.a
Therefore, [(5000*R*2)/100] + [(3000*R*4)/100] =2200
100R +120R = 2200
R = 10%

6. How much will be the compound interest to be paid on a principal amount of Rs 85,000/- after 3 years at the rate of 6 p.c.p.a?1. Rs 16623.36/-
2. Rs 16236.36/-
3. Rs 16326.36/-
4. Rs 16632.36/-
5. None of these

Answer & Explanation

Answer :- 2

Explanation :-

Amount= P (1+R/100)^T
A = 85000(1+ (6/100))^3
=>85000*(53/50)*(53/50)*(53/50)
=>2530909/25
Amount= 101236.36 Rs.
So,   C.I  =  101236.36 – 85000
= 16236.36