A sum is being lent at 20 % per annum compound interest.what is the ratio of increase in amount of 4th year to 5th year?

Correct Answer: 2522

Explanation:

Principal = Rs. 16000; Time = 9 months =3 quarters;
Rate = 20% per annum = 5% per quarter.
Amount = Rs. [16000 x (1+(5/100))3] = Rs. 18522.

 

 

 

CJ. = Rs. (18522 - 16000) = Rs. 2522

Correct Answer: 5400

Explanation:

Interest for 1 year is the same whether it's simple interest or the compound interest.

Now interest of third year = 8575 - 7350 = 1225; means principal for this interest is 7350 if comound interest is takenIf 7350 is the principal interest = 1225

if 100 is the principal interest =(1225/7350) * 100 = 50/3 %

When a thing increases for two successive times the overall increase on initial amount = a + b + (a * b)/100

Therefore overall interest for two years = 50/3 + 50/3 + [(50/3)*(50/3)]/100 = 325/9 %

Therefore amount after 2 years = 100 + 325/9 = 1225/9

If 1225/9 is the amount principal =100

if 7350 is the amount principal =(900/1225)*7350 =5400

So sum = 5400; Rate = 50/3 %

Correct Answer: 1261

Explanation:

Clearly, Rate = 5% p.a., Time = 3 years, S.I.= Rs. 1200. . .
So principal=RS [100*1200]/3*5=RS 8000
Amount = Rs. 8000 x [1 +5/100]^3 - = Rs. 9261.
.. C.I. = Rs. (9261 - 8000) = Rs. 1261.

Correct Answer: Rs.8000

Explanation:

Compound Interest on P at 10% for 2 years when interest is compounded half-yearly

 

= P 1 + R 2 100 2 T - P = P 1 + 1 20 4 - P = P 21 20 4 - P

 

Simple Interest on P at 10% for 2 years =  P R T 100 = P × 10 × 2 100 = P 5

 

Given that difference between compound interest and simple interest = 124.05

  P * 21 20 4 - P - P 5 = 124 . 05

 

=> P 21 20 4 - 1 - 1 5 = 124 . 05

 P=8000

Correct Answer: I only or II and III only

Explanation:

I . P * R * 5 100 = P ? R = 20

  I I . P 1 + R 100 2 - P - P * R * 2 100 = 400 = > p R 2 = 4000000

  I I I . P * R * 1 100 = 2000 = > P R = 200000

  P R 2 P R = 4000000 200000 ? R = 20

 

Thus I only or (II and III) give answer.

 

 Correct answer is (D)

Correct Answer: Rs.98.56

Explanation:

difference in C.I and S.I in 2years =Rs.32

S.I for 1year =Rs.400

S.I for Rs.400 for one year =Rs.32

rate=[100*32)/(400*1)%=8%

difference between in C.I and S.I for 3rd year

=S.I on Rs.832= Rs.(832*8*1)/100=Rs.66.56

Correct Answer: 3years

Explanation:

Principal = Rs. 1000; Amount = Rs. 1331; Rate = 10% p.a. Let the time be n years. Then,
[ 1000 (1+ (10/100))^n ] = 1331 or (11/10)^n = (1331/1000) = (11/10)^3
n = 3 years

Correct Answer: Rs.3972

Explanation:

 

Let P = Rs. 100. Then, S.I. Rs. 60 and T = 6 years.

 

R= 100 * 60 100 * 6 =10% p.a

 

Now, P = Rs. 12000. T = 3 years and R = 10% p.a.

 

C.I= R s . 12000 * 1 + 10 100 3 - 1
       =Rs.3972

Correct Answer: 11%

Explanation:

Difference in C.I and S.I for 2 years

= Rs(696.30-660)

=Rs. 36.30.

 

S.I for one years = Rs330.

S.I on Rs.330 for 1 year =Rs. 36.30 

 

Rate

= (100x36.30/330x1)%

= 11%

Correct Answer: Rs. 1400

Explanation:

We know thatThe Difference between Compound Interest and Simple Interest for n years at R rate of interest is given by  C . I n - S . I n = P R 100 n

Here n = 2 years, R = 20%, C.I - S.I = 56

$$\begin{gathered} 56 = P 20 100 2 \\ = > P = 56 x 5 2 \\ = > P = 56 x 25 \\ = > P = Rs . 1400 \end{gathered}$$