A shopkeeper gives one kite free to a customer on the purchase of 24 kites. If he doubles the discount, how many kites should he give free on the purchase of 69 kites?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 6
A free article is a discount: the customer takes home the paid kites plus the free ones but pays only for the paid ones, so the discount is the free kites as a part of all the kites he gets.
Now: pays for 24, gets 25, discount \(\displaystyle =\frac{1}{25}\times100=4\%\)
Doubled discount \(=8\%\)
On 69 kites let \(x\) kites be free; he gets \(69+x\) kites
\(\displaystyle \frac{x}{69+x}=\frac{8}{100}\)
\(100x=552+8x\), so \(92x=552\)
\(x=6\)
Check: \(\displaystyle \frac{6}{75}\times100=8\%\)
He should give 6 kites free.