Question

A group of students conducted a survey to find out about the preferred mode of transportation to school among their classmates. They surveyed 200 students from their school. The results of the survey are as follows: 120 students preferred to walk to school. 25% of the students preferred to use bicycles. 10% of the students preferred to take the bus. Remaining students preferred to be dropped off by car.

Based on the above information, answer the following questions:

1. What is the probability that a randomly selected student does not prefer to walk to school?
2. Find the probability of a randomly selected student who prefers to walk or use a bicycle.
3. 1. One day 50% of walking students decided to come by bicycle. What is the probability that a randomly selected student comes to school using a bicycle on that day?
                                           OR
   2. What is the probability that a randomly selected student prefers to be dropped off by car?

Answer 1

i. Number of students who do not prefer to walk = 200 − 120 = 80

P(selected student doesn’t prefer to walk) = `80/200` or `2/5`

ii. Total number of students who prefer to walk or use a bicycle = 120 + 50 = 170

P(selected student prefers to walk or use a bicycle) = `170/200` or `17/20`

iii. A. 50% of walking students who used bicycles = 60

Number of students who already use bicycles = 50

P(selected student uses bicycle) = `110/200` or `11/20`

OR

B. Number of students who preferred to be dropped off by car

= 200 − (120 + 50 + 20)

= 10 students

P(selected student is dropped by car) = `10/200` or `1/20`