GMAT Practice Question: On a certain transatlantic crossing, 20 percent of a ship's passengers held round-trip tickets...
Question
On a certain transatlantic crossing, 20 percent of a ship's passengers held round-trip tickets and also took their cars aboard the ship. If 60 percent of the passengers with round-trip tickets did not take their cars aboard the ship, what percent of the ship's passengers held round-trip tickets?
- 33 1/3 %
- 40 %
- 50 %
- 60 %
- 66 2/3 %
Topics: word problems, percentages, translations, sets & groups
Solution
Step 1
We first create an unknown for the percentage of passengers who held round-trip tickets.
R=percent of passengers with round-trip tickets
Step 2
We translate "60 percent of the passengers with round-trip tickets did not take their cars aboard the ship", which means that the remaining percent of those passengers did take their cars.
R-60/100R=40/100R
Step 3
We translate "20 percent of the ship's passengers held round-trip tickets and also took their cars aboard the ship" as the fraction of all passengers who both held round-trip tickets and took their cars.
40/100R=20/100
Step 4
We solve the linear equation for the unknown by isolating it.
40/100R=20/100 R=20/10040/100 =20/40 =1/2=50%
Answer
50%
