Page 308 - Start Up Mathematics_7

2. A bag contains 10 marbles of which 8 are red. One marble is drawn at random. The probability
that it is not red is:

8 6 4 2
(a) (b) (c) (d)
10 10 10 10
3. If a letter is taken out from a bag containing letters of the word “SNAKE”, the probability of
picking A is:
1 2 1
(a) (b) (c) (d) 1
5 5 2
4. If a slip of paper is drawn from a jar containing 12 slips with different months of the year
written on it, then probability of the month starting with letter ‘J’ is:
1 2 3 4
(a) (b) (c) (d)
12 12 12 12
5. If a card is drawn from a well-shuffled deck of 52 playing cards, the probability of it being
both red and black is:
1 1
(a) 0 (b) (c) (d) 1
4 2
6. If a die is thrown once, the sample space not having equally likely outcomes is:
(a) {even number, odd number} (b) {prime number, composite number}
(c) {number whose value is at most 3, number whose value is at least 4}
(d) none of these

7. The probability that it will rain tomorrow is 80%. The probability that it will not rain tomorrow
is:
1 2 3 4
(a) (b) (c) 5 (d) 5
5
5
8. Two dice are thrown simultaneously. The number of outcomes having exactly one even
number is:
(a) 18 (b) 27 (c) 9 (d) 12

solve Mentally
True or False
1. Probability of an event which is sure to happen is 1.
2. A random experiment is one whose outcomes are predictable.

3. If a fair coin is tossed 4 times, the exact number of heads cannot be predicted accurately.
1
4. The probability that the ceiling of the room in which you are sitting collapses is .
2
5. Probabilities are ratios which can be expressed as fractions, decimals or percentages.
6. Experimental probability comes closer and closer to theoretical probability if the number of
trials are large and are increasing.
7. The experimental probability of getting a head can be 1 if the coin is tossed a few times only.

Fill in the Blanks

1. Probability of an ____________ event is 0.
2. Probability is measured on a scale of _______ to _______.

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