23
Q:

# At What rate percent per annum will a sum of money double itself is 12 years?

Q:

Rs.1500 is divided into two parts such that if one part is invested at 6% and the other at 5% the whole annual interest from both the sum is Rs.85. How much was lent at 5% ?

 A) Rs. 500 B) Rs. 245 C) Rs. 1250 D) Rs. 635

Explanation:

(kx5x1)/100 + [(1500 - k)x6x1]/100 = 85

5k/100 + 90 – 6k/100 = 85

k/100 = 5

=> k = 500

1 2
Q:

Althaf borrows Rs. 1500 from two moneylenders. He pays interest at the rate of 12% per annum for one loan and at the rate of 14% per annum for the other. The total interest he pays for the entire year is Rs. 186. How much does he borrow at the rate of 12% ?

 A) Rs. 300 B) Rs. 400 C) Rs. 1200 D) Rs. 1100

Explanation:

Let Althaf lent Rs. A at 14% per year.
Hence, Money lent at 12% = (1500-A);
Given, total interest = Rs. 186.
{(A x 14x 1)/100} + {[(1500-A) x 12 x 1/100]} = 186;
14A/100 + (18000 -12A)/100 = 186;
14A + 18000 - 12A = 186x100;
2A = 18600-18000;
A = 600/2 = Rs. 300.
Hence, money lent at 12% = 1500-300 = Rs. 1200.

1 84
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 %.

1 178
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

4 332
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 %