Quant review 2018 Question 142

Hello Dablu,

In questions like these, you need to spend time on understanding what could be the reference value on which the percentage values could be applied. I want you to know that percentage values themselves do not mean anything unless you apply them on a reference value.

In this question, I'd take the reference value as the number of people who had round tickets. Since 60% is \(\frac{3}{5}\), I would take 50 as the total number of people who bought round tickets. This means that 30 of them did not take their cars aboard the ship. This leaves us with 20 who HAD round tickets and TOOK their cars aboard the ship.

But the question says that 20% of the total passengers HAD round tickets and TOOK their cars aboard the ship. This means the 20 in the paragraph above represents 20% of the total passengers.

Hence, total passengers = 100.

Passengers with round tickets = 30 + 20 = 50.

Required percentage = \(\frac{50}{100}\) = \(\frac{1}{2}\) = 50%.
The correct answer option is C.

Hope that helps!