(1) Which number cannot represent a probability?
A. 2/3
B. 1.5
C. 15%
D. 0.7
Solution:
B. 1.5
Explanation:
As probability of any event lies between 0 and 1, the answer is option B = 1.5, which is greater than 1.
(2) A die is rolled. What is the probability that the number appearing on upper face is less than 3?
A. 1/6
B. 1/3
C. 1/2
D. 0
Solution:
B. 1/3
Explanation:
Favorable outcomes = (1, 2) = 2
Total number of outcomes=6
Probability that the number appearing on upper face is less than 3 = 2/6 = 1/3
(3) What is the probability of the event that a number chosen from 1 to 100 is a prime number?
A. 1/5
B. 6/25
C. 1/4
D. 13/50
Solution:
B. 6/25
Explanation:
Favorable outcomes=24
Total number of outcomes=100
Probability that the number a number chosen from 1 to 100 is a prime number = 24/100 = 6/25
(4) There are 40 cards in a bag. Each bears a number from 1 to 40. One card is drawn at random. What is the probability that the card bears a number which is a multiple of 5?
A. 1/5
B. 3/5
C. 4/5
D. 1/3
Solution:
A. 1/5
Explanation:
Favorable outcomes=8
Total number of outcomes=40
Probability that the card bears a number which is a multiple of 5 = 8/40 = 1/5
(5) If n(A) = 2, P(A) = 1/5, then n(S) =?
A. 10
B. 5/2
C. 2/5
D. 1/3
Solution:
A. 10
Explanation:
Probability, P(A) = n (A)/ n (s)
⇒ 1/5 = 2/ n(s)
n(S)=10