A hat seller had some hats. He sells 55% hats and still has 90 hats. Originally, he had:

Question: A hat seller had some hats. He sells 55% hats and still has 90 hats. Originally, he had:

Solution:
Let,
The hat seller had = x hats.

ATQ,
(100 - 55)% of x = 90
⇒ 45% of x = 90
⇒ 45x/100 = 90
⇒ 9x/20 = 90
⇒ x = (90 × 20)/9
∴ x = 200

∴ Originally, he had 200 hats