10
Q:

A person lends Rs. 300 to A at 4% and Rs.540 to B at 6% for the same time. if the total amount that he gets at the end is Rs. 1032. What is the time?

Q:

An amount doubles itself in 15 years. what is the rate of interest ?

 A) 7.85 % B) 9.41% C) 6.66 % D) 4.21 %

Explanation:

Let the principle be Rs. P
As the amount double itself the interest is Rs. P too
So P = P x r x 15/100
=> r = 100/15 = 20/3 % = 6.66 %.

1 29
Q:

A Certain sum of money an amounts to Rs 2500 in a span Of 5 years and further to Rs.3000 in a span of 7 years at simple interest The sum is ?

 A) Rs. 1800 B) Rs. 2000 C) Rs. 1400 D) Rs. 1250

Explanation:

2500 in 5th year and 3000 in 7th year
So in between 2 years Rs. 500 is increased => for a year 500/2 = 250
So, per year it is increasing Rs.250 then in 5 years => 250 x 5 = 1250
Hence, the initial amount must be 2500 - 1250 = Rs. 1250

3 117
Q:

A simple interest earned on certain amount is triple the money when invested for 16 years.what is the interest rate offered ?

 A) 13.33 % B) 14.25 % C) 16.98 % D) 18.75 %

Explanation:

Given,
S.I = 3 Principal Amount
=> 3A = A x 16 x R/100
By solving, we get
=> R = 18.75%

4 77
Q:

If the rate increases by 2%, the simple interest received on a sum of money increases by Rs. 108. If the time period is increased by 2 years, the simple interest on the same sum increases by Rs.180. The sum is ?

 A) Rs. 540 B) Rs. 415 C) Rs. 404 D) Data is not sufficient

Explanation:

Let the sum be Rs. p, rate be R% p.a. and time be T years.
Then,

$\inline \fn_jvn \small \left ( \frac{p \times(R+2)\times T }{100} \right )-\left ( \frac{p\times R\times T}{100} \right )=108 \Rightarrow 2pT = 10800.....(1)$

And, $\inline \fn_jvn \small \left ( \frac{p\times R\times (T+2)}{100} \right )-\left ( \frac{p\times R\times T}{100} \right )= 180 \Rightarrow 2pR = 18000.....(2)$

Clearly, from (1) and (2), we cannot find the value of p
So, the data is not sufficient.

2 180
Q:

Question :

What is the sum which earned interest ?

Statements :

a. The total simple interest was Rs. 9000 after 9 years.
b. The total of sum and simple interest was double of the sum after 6 years.

 A) Only a is sufficient B) Neither a nor b is sufficient C) Only b is sufficient D) Both a and b sufficient

Explanation:

Let the sum be Rs. x
a. gives, S.I = Rs. 9000 and time = 9 years.
b. gives, Sum + S.I for 6 years = 2 x Sum

$\fn_jvn&space;\small&space;\Rightarrow$ Sum = S.I for 6 years.
Now, S.I for 9 years = Rs. 9000
S.I for 1 year = Rs. 9000/9 = Rs. 1000.
S.I for 6 years = Rs. (1000 x 6)= Rs. 6000.

$\fn_jvn&space;\small&space;\therefore$ x = Rs. 6000

$\fn_jvn&space;\small&space;\therefore$ Thus, both a and b are necessary to answer the question.