PROBABILITY

The table shows the visitors to park on a Sunday. The relative frequencies for adult, girl and boy consecutively are ...

• 70%, 90%, 40%

• 35%, 45%, 20%

• 7%, 9%, 4%

• 3.5%, 4.5%, 2%

The relative frequency of students who go on a vacation during term break is 80%. How many students would you expect to stay at home if there are 400 students in a school?

• 20 students

• 80 students

• 320 students

• 400 students

A computer repair company keeps record of all the repairs it makes to laptop. The table shows  information about all the repairs made in 2018. Estimate the probability that the repair will cost between 100 - 300 Euros.

• 30/120

• 38/120

• 68/120

• 83/120

A potter made 100 plates. 10 of them cracked. Estimate the probability  that the next plate the potter makes cracks.

• 90%

• 70%

• 30%

• 10%

An ordinary 6-sided dice is rolled 250 times. How many times would you expect to get a prime number?

• 250 times

• 166 times

• 125 times

• 83 times

In a video racing game, an obstacle randomly appears on the race track five times every 40 laps. Work out the probability that an obstacle appears on the track during a particular lap.

• 1/20

• 1/10

• 1/8

• 1/2

In a survey of adults who set themselves some fitness targets, 5% achieved all of them and 15% achieved some of them. Another fitness survey questions 400 adults. How many would you expect to achieve all of their targets.

• 5 people

• 20 people

• 60 people

• 100 people

Clayton asked the students in his class how many coins they each had in their pockets.

Estimate the probability that a student had less than 9 coins.

• 7/32

• 12/32

• 6/32

• 25/32

During the past 30 days, Jana has missed her school bus on 4 occasions. Estimate the probability that Jana will miss her school bus tomorrow.

• 4/30

• 6/30

• 10/30

• 15/30

Joe and Cecil each test the same coin to see if it is fair. Joe flips the coin 50 times and and gets 31 heads. Cecil flips the coin 100 times and gets 67 heads. Who has given the more reliable estimate of getting a head?

• JOE

• CECIL