8TH MATHS PART 2 CHAPTER 3 DATA HANDLING-3 EXERCISE 3.3
NCERT 8TH MATHS PART 2 CHAPTER 3
DATA HANDLING EXERCISE 3.3
Question 1:
List the outcomes you can see in these experiments.
(a) Spinning a wheel
(b) Tossing two coins together
ANSWER:
(a) On spinning the given wheel, the possible outcomes are A, B, C, D.
(b) By tossing two coins together, the possible outcomes are HT, TH, HH, TT where H and T represents Head and Tail of the coins respectively.
Question 2:
When a die is thrown, list the outcomes of an event of getting
(i) (a) a prime number (b) not a prime number
(ii) (a) a number greater than 5 (b) a number not greater than 5
ANSWER:
When a dice is thrown, the possible outcomes are 1, 2, 3, 4, 5, and 6.
(i) (a) Out of these outcomes, 2, 3, 5 are prime numbers. Hence, these are the outcomes of an event of getting a prime number on the face of a dice.
(b) Out of these outcomes, 1, 4, 6 are not prime numbers. Hence, these are the outcomes of an event of not getting a prime number on the face of a dice.
(ii) (a) Out of these outcomes, a number greater than 5 is possible when 6 comes on the face of the dice.
(b) Out of these outcomes, a number not greater than 5 is possible when the number on the face of the dice is any one of the outcomes 1, 2, 3, 4, 5.
Question 3:
Find the.
(a) Probability of the pointer stopping on D in (Question 1 − (a))?
(b) Probability of getting an ace from a well shuffled deck of 52 playing cards?
(c) Probability of getting a red apple. (See figure below)
ANSWER:
(i) The pointer can stop at one of the following regions.
A, A, B, C, D
Out of these 5 cases, it is possible only in 1 case that the pointer will stop at region D.
Therefore, probability that the pointer will stop at region D =
(ii) There are 52 cards in a deck of cards and there are 4 ace cards in 1 deck of cards.
Probability of getting an ace card =
(iii) There are a total of 7 apples, out of which, 4 are red and 3 are green.
Probability of getting a red apple =
Question 4:
Numbers 1 to 10 are written on ten separate slips (one number on one slip), kept in a box and mixed well. One slip is chosen from the box without looking into it. What is the probability of.
(i) getting a number 6?
(ii) getting a number less than 6?
(iii) getting a number greater than 6?
(iv) getting a 1-digit number?
ANSWER:
(i) There are 10 slips in the box. However, 6 is written only on 1 slip.
Probability of getting a number 6 =
(ii) The numbers less than 6 are 1, 2, 3, 4, 5.
Probability of getting a number less than 6 =
(iii) The numbers greater than 6 are 7, 8, 9, 10.
Probability of getting a number greater than 6 =
(iv) There are 9 numbers which are single digit numbers.
1, 2, 3, 4, 5, 6, 7, 8, 9
Probability of getting a single digit number =
Question 5:
If you have a spinning wheel with 3 green sectors, 1 blue sector and 1 red sector, what is the probability of getting a green sector? What is the probability of getting a non blue sector?
ANSWER:
Total sectors = 3 + 1 + 1 = 5
There are 5 sectors and we can get a green sector in three cases.
Probability of getting a green sector =
We will get a non blue sector when we will get either a green sector or a red sector. Hence, 4 cases of such type are possible in which we will get a non blue sector.
Probability of getting a non blue sector =
Question 6:
Find the probabilities of the events given in Question 2.
ANSWER:
(i) (a) Out of 6 possible outcomes, a prime number can be obtained in three cases. Therefore, probability of getting a prime number =
(b) Out of 6 possible outcomes, a prime number may not be obtained in three cases.
Therefore, probability of getting not a prime number =
(ii) (a) Out of 6 possible outcomes, a number greater than 5 can be obtained in only 1 case.
Therefore, probability of getting a number greater than 5 =
(b) Out of 6 possible outcomes, a number not greater than 5 can be obtained in 5 cases.
Therefore, probability of getting a number not greater than 5 =