ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 17 Data Handling Ex 17.4
Question 1.
Tell whether the following is certain to happen, impossible to happen, can happen but not certain:
(i) You are older today than yesterday.
(ii) Two hundred people can sit in a Maruti car.
(iii) A tossed coin will land heads up.
(iv) A die when tossed shall land up with 8 on top.
(v) India will win the next test series.
(vi) Tomorrow will be a cloudy day.
(vii) The next traffic light seen will be green.
Solution:
(i) Certain to happen.
(ii) Impossible, as two hundred can’t sit in a car.
(iii) It can happen but not certain.
(iv) Impossible as a die has 1 to 6 marks.
(v) It can happen but not certain.
(vi) It can happen but not certain.
(vii) It can happen but not certain.
Question 2.
A coin is flipped to decide which team starts the game. What is the probability that your team will start the game?
Solution:
A coin is flipped to decide which team starts the game (A coin has two sides)
Possibility (P) = \(\frac { 1 }{ 2 }\)
Question 3.
There are 6 marbles in a box with numbers 1 to 6 marked on them.
(i) What is the probability of drawing a marble with number 5?
(ii) What is the probability of drawing a marble with number 2?
Solution:
Number of total marbles with number 1 to 6
(i) Probability of drawing marble of getting number 5 = \(\frac { 1 }{ 6 }\)
(ii) Probability of drawing a marble of getting number 2 = \(\frac { 1 }{ 6 }\).
Question 4.
A die is tossed once. Find the probability of getting
(i) a number less than 3
(ii) a prime number
(iii) a number greater than 2
Solution:
A die is tossed once
Total number of favourable outcome = 6
(i) Probability of getting a number less than three
(1, 2) = \(\frac { 2 }{ 6 }\) = \(\frac { 1 }{ 3 }\)
(ii) Probability of getting a prime number (2, 3, 5) = \(\frac { 3 }{ 6 }\) = \(\frac { 1 }{ 2 }\)
(iii) Probability of getting a number greater than 2 (3, 4, 5, 6) = \(\frac { 4 }{ 6 }\) = \(\frac { 2 }{ 3 }\)
Question 5.
A box contains 3 defective mangoes and 21 good mangoes. One mango is drawn from the box at random. Find the probability of getting
(i) a defective mango
(ii) a good mango
Solution:
In a box, there are 3 defective mangoes and 21 good mangoes.
Total mangoes = 3 + 21 = 24
One mango is drawn at random, then
(i) Probability of a defective mango = \(\frac { 3 }{ 24 }\) = \(\frac { 1 }{ 8 }\)
(ii) Probability of a good mango = \(\frac { 21 }{ 24 }\) = \(\frac { 7 }{ 8 }\)
Question 6.
A card is drawn from a well-shuffled pack of 52 playing cards. Find the probability of getting
(i) a red card
(ii) a king
(iii) a card of spades
Solution:
Number of playing cards = 52
In which 13 cards are of each suit and number suit is 4.
There are two colour: Red and Black.
Now one card is drawn at random:
(i) Probability of being a red card = \(\frac { 26 }{ 52 }\) = \(\frac { 1 }{ 2 }\)
(ii) Probability of being a king = \(\frac { 4 }{ 52 }\) = \(\frac { 1 }{ 13 }\) (There are 4 cards of king)
(iii) Probability of being a card of spades = \(\frac { 13 }{ 52 }\) = \(\frac { 1 }{ 4 }\)