Question

For every set of 19 kites sold, the vendor gives 1 kite extra, free of cost. In order to give a discount of 10%, the no. of extra kites he should give in a scale of 27 kites to the nearest integer is
(a) 1
(b) 2
(c) 3
(d) 4

Answer 1

Hint: First find the discount he is giving at first, i.e by selling 19 kites and 1 kite free along with it. So, we will have 20 kites in total and we can divide 1 by 20 to get the discount. Now make the necessary changes to change the discount to 10%. From this, we will get the number of kites, including free kites sold. After the changes, find the extra kites in the case of 27 kites.

Complete step-by-step answer:
At first, we can write the given offer by salesmen as:
19 kites sold then 1 kite is free.
So, that means, 1 kite price is gone if 20 kites are sold. So, we can express it as $\dfrac{1}{20}$ . Now, if we want the percentage, we multiply it with 100 and get it as 5%.
Now, it is given that we have to find the extra kites when the discount is 10%.
So, we need to multiply the above fraction by 2 to get 10%. Which will be the fraction $\dfrac{1}{10}$.
That means, 1 kite price is gone if 10 kites are sold. So, we can say that if 9 kites are sold, then 1 kite is free.
So, for our case if 27 kites are sold, we need to multiply the above condition with 3. So, we get that if 27 kites are sold then 3 kites must be free.
So, 3 kites are the answer for the required question.

So, the correct answer is “Option c”.

Note: Generally, students use the first condition of 5% and solve the question they forget to take that the discount is differently given as 10%, they think this is 10% without calculating. But actually, it is 5%. They do cross multiplication methods. So, read every point in the question carefully to reach a correct answer.