1). What would be the simple interest accrued in 4 yr on a principle of RS. 18440 at the rate 15% per annum?
A). RS.11075 
B). RS.12250 
C). RS.11500 
D). RS.11064 
Correct Answer: RS.11064 Given, P = 18440, R = 15%, T =4
Simple interest (SI) = \( \Large \frac{T\times P\times R}{100} \)
=\( \Large \frac{4\times 18440\times 15}{100} \) = RS.11064

2). Rakesh lent out RS. 8750 at 7% annual interest. Find the simple interest in 3 yr.
A). RS.1870 
B). RS.1837.50 
C). RS.1560 
D). RS.2200 
Correct Answer: RS.1837.50 Given, P = RS. 8750, R =7%, T=3y
According to the formula,
SI = \( \Large \frac{P\times R\times T}{100} \)=\( \Large \frac{8750\times 7\times 3}{100} \)
= RS.1837.50

3). What will be simple interest for 1 yr and 4 months on a sum of RS. 25800 at the rate of 14% per annum?
A). RS.4816 
B). RS.2580 
C). RS.4816.75 
D). RS.4815 
Correct Answer: RS.4816 Here, P = RS. 25800, R = 14%
T = lyr 4 months
= \( \Large1+ \frac{4}{12} =1+\frac{1}{3}=\frac{4}{3}yr \)
According to the formula,
SI= \( \Large \frac{P\times R\times T}{100} \)=\( \Large \frac{25800\times 14\times 4/3}{100} \)
= \( \Large \frac{258\times 14\times 4}{3} \)
= RS.4816

4). The sum which amounts to RS. 364.80 in 8 yr at 3.5% simple interest per annum is
A). RS.285 
B). RS.280 
C). RS.275 
D). RS.270 
Correct Answer: RS.285 Given, t = 8 yr, r= 3.5%, A=Rs.364.80
Let amount = RS. P
Since, A = \( \Large P \times \left(1+\frac{RT}{100}\right) \)
364.80 = P\( \Large \left( 1+ \times \left(\frac{3.5 \times 8}{100}\right) \right) \)
=> 364.80 = P\( \Large \left( 1+ \left(\frac{35\times 8}{1000}\right) \right) \)
=> \( \Large \frac{3648}{10} = P\left(\frac{128}{100}\right) \)
=> P=\( \Large \frac{3648}{128} \)=RS.285

5). A sum of Rs. 2668 amounts to Rs. 4669 in 5yr at the rate of simple interest. Find the rate per cent.
A). 15.20% 
B). 14.90% 
C). 16% 
D). 15% 
Correct Answer: 15% Here, P = RS. 2668, T = 5yr, A = RS. 4669
We know that,
Amount (A) = Principal (P) + (Simple Interest)SI
4669 = 2668 + SI
=> SI = 4669  2668 = RS.2001
Again, SI = \( \Large \frac{P\times R\times T}{100} \)
2001 = \( \Large \frac{2668\times R\times 5}{100} \)
=> R=\( \Large \frac{2001\times 100}{2668\times5}=\frac{2001\times 5}{667} \)=15%

6). Find the difference in amount and principal for RS. 4000 at the rate of 5% annual interest in 4 yr.
A). RS.865.50 
B). RS.865 
C). RS.400 
D). RS.800 
Correct Answer: RS.800
The required difference in amount and principal is SI = A  P.
Here, P = RS. 4000, R = 5%, T = 4 yr
According to the formula,
SI = \( \Large \frac{P\times R\times T}{100} \)
= \( \Large \frac{4000\times 5\times 7}{100} \) =RS.800

7). Kriya deposits an amount of RS. 65800 to obtain a simple interest at the rate of 14% per annum for 4 yr. What total amount will Kriya get at the end of 4 yr?
A). RS.102648 
B). RS.115246 
C). RS.125578 
D). RS.110324 
Correct Answer: RS.102648
Here, P = RS. 65800, R = 14%, T = 4 yr
Hence, SI = \( \Large \frac{65800\times 14\times 4}{100} \)= RS. 36848
Required amount = P + SI
= 65800 + 36848 = RS. 102648

8). A sum becomes its double in 10 yr. Find the annual rate of simple interest.
A). 1% 
B). 5% 
C). 10% 
D). 20% 
Correct Answer: 10%
Let the sum be P.
Then, after 10 yr
Sum = 2P
SI = 2P  P = P
Now, SI=\( \Large \frac{P\times R\times T}{100} \)=> P=\( \Large \frac{P\times R\times 10}{100} \)
R = 10%

9). A certain sum becomes 3 fold at 4% annual rate of interest. At what rate, it will become 6 fold?
A). 10% 
B). 12% 
C). 8% 
D). 9% 
Correct Answer: 10%
Let the sum be P.
Then, for 4%
SI = (3PP)=2P
2P = \( \Large \frac{P\times 4\times T}{100} \)=> 1=\( \Large \frac{2T}{100} \)=\( \Large \frac{T}{50} \)
T = 50yr
Again, for another rate (R),
SI =(6PP) =5P
5P = \( \Large \frac{P\times R\times 50}{100}=\frac{PR}{2} \)
R = 10%

10). A sum becomes 6 fold at 5% per annum. At what rate, the sum becomes 12 fold?
A). 10% 
B). 12% 
C). 9% 
D). 11% 
Correct Answer: 11% SI at 5% = 6PP=5P
5P=\( \Large \frac{P\times 5\times T}{100} \)
=> T=100yr
Now,for new rate (R),
11P=\( \Large \frac{P\times R\times 100}{100} \)
R=11%
