# Simple Interest Quiz Set 002

### Question 1

The interest on a certain principal sum is 1/4 times the sum. What is R, the rate of interest, if the time is R years?

A

5%.

B

\$5{1/2}\$%.

C

6%.

D

\$4{1/2}\$%.

Soln.
Ans: a

I = P × (1/4), so we can write P × (1/4) = P × (R/100) × R. Cancelling P and solving for R, we get, R = \$√{100 × 1/4}\$ = 5%.

### Question 2

The interest on Rs. 7500 @3% for a certain number of days starting from Jan 1, 2001 is Rs. 45. How many days?

A

73 days.

B

74 days.

C

72 days.

D

75 days.

Soln.
Ans: a

We have r = 3%, P = 7500, I = 45, so t = \${100 × 45}/{7500 × 3}\$. We get t = 1/5. The given year is not a leap year. So it has 365 days. Since 365/5 = 73, the number of days is 73.

### Question 3

An investor puts an amount of Rs. 900 in a simple interest scheme. If the rate of interest is 5% per month, how long does he have to wait for getting an amount of Rs. 1035?

A

\${1/4}\$ year.

B

\${1/3}\$ year.

C

\${5/12}\$ year.

D

\${1/2}\$ year.

Soln.
Ans: a

The interest is I = 1035 - 900 = 135. So T = \$(I × 100)/(R × P)\$. Solving, we get T = \$(135 × 100)/(5 × 900)\$ = 3 months.

### Question 4

An investor puts an amount of Rs. 4200 in a simple interest scheme. If it amounts to Rs. 5712 in 4 years @9%, what would it had amounted to had the rate been 2% more?

A

Rs. 6048.

B

Rs. 6148.

C

Rs. 5948.

D

Rs. 6248.

Soln.
Ans: a

Shortcut is required here. The addition would be same as if R = 2%, T = 4 years and P = Rs. 4200, which is \${4200 × 2 × 4}/100\$ = 336. So new amount is 5712 + 336 = Rs. 6048.

### Question 5

An investor puts an amount of Rs. 4500 in a simple interest scheme. If the rate of interest is 4% per month, how long does he have to wait for getting an amount of Rs. 5940?

A

\${2/3}\$ year.

B

\${3/4}\$ year.

C

\${5/6}\$ year.

D

\${11/12}\$ year.

Soln.
Ans: a

The interest is I = 5940 - 4500 = 1440. So T = \$(I × 100)/(R × P)\$. Solving, we get T = \$(1440 × 100)/(4 × 4500)\$ = 8 months.