CAT 1993 — QA Question 19
3 Variable EquationsEasy
Passage / Data
Use the following information:
Eighty five children went to an amusement park where they could ride on the merry – go round, roller coaster, and Ferris wheel. It was known that 20 of them took all three rides, and 55 of them took at least two of the three rides. Each ride cost Re.1, and the total receipt of the amusement park was Rs.145.
How many children did not try any of the rides?
Answer & solution
- A
5
- B
10
15
- D
20
Solution
Let x, y and z be the number of children who took 1 rides, 2 rides and 3 rides respectively.
Since z = 20 and y + z = 55, y = 35.
Then, total number of rides = x + 2y + 3z = 145
⇒ x + 2 × 35 + 3 × 20 = 145
⇒ x = 15
Number of children, who did not try any of the rides
= 85 – (x + y + z)
= 85 – (15 + 35 + 20) = 15
Hence, option (c).