1500 families with 2 children were selected randomly, and the following data were recorded:

Compute the probability of a family, chosen at random, having
(i) 2 girls  (ii) 1 girl (iii) No girl
also, check whether the sum of these probabilities is 1.

In a particular section of Class IX, 40 students were asked about the months of their birth, the following graph was prepared for the data so obtained. Find the probability that a student of the class was born in August.

To know the opinion of the students about the subject statistics, a survey of 200 students was conducted. The data is recorded in the following table:

 Find the probability that a student chosen at random
(i) likes statistics,
(ii) does not like it

Eleven bags of wheat flour, each marked 5 kg, actually contained the following weights of flour (in kg):
4.97, 5.05 ,5.08 ,5.03 ,5.00 ,4.86, 5.08, 4.98 ,5.04, 5.07 ,5.00
Find the probability that any of these bags chosen at random contains more than 5 kg of flour.

In a cricket match, a batsman hits a boundary 6 times out of 30 balls she plays.Find the probability that she did not hit a boundary.

Three coins are tossed simultaneously 250 times. The distribution of various outcomes is listed below:
(i) Three tails: 30
(ii) Two tails: 70
(iii) One tail : 90
(iv) No tail: 60
Find the respective probability of each event and check that the sum of all the probabilities is 1.

The percentage of marks obtained by a student in the monthly unit tests are given below:

Based on this data, find the probabi lity that the
(a) student gets less than 60% marks in a unit test
(b) student gets at least 60% marks in a unit test

In a survey of 200 men, it was found that 65 men take only coffee, 35 take only tea, 25 do not take either and the rest take both coffee and tea. Find the probability that a man selected at random:
(a) takes coffee
(b) takes only tea

Given below is the frequency distribution of salary in Rs of 80 workers in a factory.

Find the probability that the salary of a worker selected at random is:
(i) Less than 4000
(ii) More than or equal to 3000
(iii) More than or equal to 2000 but less than 5000

Over the past 200 working days, the number of defective parts produced by a machine are given in the following table:

Determine the probability that tomorrow's output will have not more than 5 defective parts.

The data regarding the number of children in a house of a colony which has 250 houses was collected and is recorded below. The houses with  number of children are recorded below:

One house is selected at random. What is the probability that it is a house which has 
(a) 2 boys?
(b) more than one child? 
(c) no children at all?

Three coins were tossed 30 times simultaneously. Each time the number of heads occurring was noted down as follows 

Prepare frequency distribution table for the data given below.

Following is the data about the months of birth of 40 students in class IX.

One student is chosen at random. Find the probability that the student chosen:
(i) was born in June
(ii) was not born in the month of June

Given below is the frequency distribution of salary (in rupees) of 80 workers in a factory.

If a worker is selected at random, find the probability that his salary is
(i) Less than Rs 3000
(ii) More than or equal to Rs 1000
(iii) More than or equal to Rs 2000 but less than Rs 4000

Two dice are thrown 400 times. Each time sum of two numbers appearing on the tops is noted as given in the following table:

What is the probability of getting a sum
(i) 5
(ii) more than 10
(iii) between 5 and 10