Page 206 - Maths Skills - 8

204 Maths

2. A die is thrown once, find the probability of getting

(i) an odd number (ii) a number less than 4 (iii) a composite number
(iv) a number divisible by 2
3. Four coins are tossed. Construct a tree diagram and list the sample space. Find the probability of
getting
(i) exactly three heads (ii) exactly two heads (iii) exactly one head

(iv) no head (v) at least one head
4. In a box, there are 11 blue marbles, 13 green marbles and 6 red marbles. If one marble is drawn at
random, find the probability of getting

(i) a red marble (ii) a blue marble (iii) a green marble
5. Two die are rolled simultaneously. Find the probability of getting
(i) a sum of 5 (ii) two 5’s (iii) a sum of 10

6. A bag contains 16 balls out of which 7 are black and rest are white. If one ball is drawn at random, find
the probability of drawing
(i) a black ball (ii) a white ball
7. If five coins are tossed simultaneously, list the sample space with the help of a tree diagram and find the
probability of getting

(i) three heads (ii) at least two heads (iii) only tails
(iv) at least one tail (v) exactly two tails

ASSESSMENT TIME

5. A collection of initial observations of anything
COMPETENCY BASED QUESTIONS
which is not organized is called:
A. Multiple-Choice Questions (i) observation (ii) raw data
1. In a histogram, heights of the rectangles
represent: (iii) range (iv) none of these
(i) class size (ii) class 6. Probability of an event lies between:
(iii) class intervals (iv) frequency (i) 0 and 1 (ii) 2 and 3

2. The number of times a particular observation (iii) –1 and 0 (iv) none of these
occurs in a given data is called its: 7. An operation that can produce some well-defined

(i) raw data (ii) range outcomes is called:
(i) an event
(ii) trial
(iii) frequency (iv) none of these (iii) an experiment (iv) probability
3. In interval 80 – 90, 90 is called: 8. When a coin is tossed, the total number of

(i) lower limit (ii) upper limit possible outcomes are:
(iii) range (iv) frequency (i) 0 (ii) 1 (iii) 2 (iv) 3
4. Tally marks are used to find: 9. When a dice is rolled, the total number of
(i) class intervals (ii) lower limits possible outcomes are:

(iii) upper limits (iv) frequencies (i) 3 (ii) 6 (iii) 5 (iv) 4