1.
The data below shows the distribution of workers in a certain secondary school.
Teacher 30 Gardeners 15
Typists 9 Cleaners 6
Clerks 12 Messengers 3
If one of the workers is on leave, the probability that he is either a teacher or a gardener is
2.
Three boys play a game of luck in which their respective chances of winning are 1/2, 1/3 and 1/4.
What is the probability that one and only one of the boys wins the game?
3.
In how many different ways can the letters of the word GEOLOGY be arranged in order?
4.
Three balls are drawn one after the other, without replacement from a bag containing 4 blue, 6 white and 5 red identical balls.
The probability that the three balls are:
one blue, one white and one red is
5.
A group of 40 adults read either newspapers or magazines.
If 20 read newspapers and 35 read magazines,
the probability that one of them reads both newspapers and magazines is
6.
Two fair dice are thrown together.
The probability that the two dice will show the same number of points is
7.
A container has 32 blue pens, 28 black pens and 20 red pens.
If a pen is selected at random,
what is the probability that it is not a red pen?
8.
Two fair coins are tossed.
The probability of getting at least one tail is
10.
The probability of obtaining a prime number in a single toss of fair die is
11.
The letters of the word MISSISSIPPI are cut and placed in a bag.
If one letter is drawn randomly from the bag,
the probability that it is neither an I nor a S is
12.
A bag contains 6 red balls, 9 blue balls and 5 green balls.
Two balls are chosen one after the other with replacement.
What is the probability that both are red?
13.
A card is drawn from an ordinary pack of 52 playing cards.
Find the probability that it is a nine or a Spade
14.
Three balls are drawn one after the other, without replacement from a bag containing 4 blue, 6 white and 5 red identical balls.
The probability of picking 2 blue and 1 red ball is
16.
A card is drawn from an ordinary pack of 52 playing cards.
Find the probability that it is a Queen of Hearts
17.
A bag containing 5 red balls and 3 green balls.
Two balls are picked, one after the other, with replacement.
The probability that the two balls selected are of different colours is
18.
A number is selected randomly from the set of integers 1 to 20 inclusive.
The probability that the number is prime is
19.
A number is selected randomly from the set of integers 1 to 20 inclusive.
What is the probability that the number is either a multiple of 3 or a multiple of 5
20.
A coin and a dice are thrown together.
Find the probability of getting a tail and a two
21.
A coin is tossed 3 times.
What is the probability of getting 2 heads and a tail in any order?
22.
A ball is selected and replaced in a bag containing blue, green and red identical balls.
The results of 50 selections are shown below
Color of ball Blue Green Red
No. of occurrences 8 15 27
The experimental probability of picking either a blue or a red ball is
23.
Two fair dice are thrown together.
The probability that the sum of the outcomes is at least 10 is
24.
Tireni throws a coin twice.
The coin is biased so the probability of landing a head is 2/5.
Find the probability that she throws two tails
25.
A die is rolled 100 times with the following outcomes:
Number 1 2 3 4 5 6
Frequency 15 20 18 14 17 16
The experimental probability of obtaining at most 4 is
