Quiz on Probability for CBSE by Pratima Nayak

If P(A) = 4/ 5 , and P(A ∩ B) = 7/ 10 , then P(B | A) is equal to

• 1/ 10 
• 17/ 20
•   1/8
•   7 /8 

If P(A ∩ B) = 7/ 10 and P(B) = 17/ 20 , then P (A | B) equals to

• 7 /8 
•  1/ 8
• 17/ 20
• 14/17

If P(A) = 3/ 10 , P (B) = 2/ 5 and P(A∪B) = 3/ 5 , then P (B | A) + P (A | B) equals to

• 1/ 4
•  1/ 3
•  7/ 12
•   5/ 12 

Two cards are drawn from a well shuffled deck of 52 playing cards with replacement. The probability, that both cards are queens is   

• 2/13
• 1/169
• 2/221 
• 1/221

Eight coins are tossed together. The probability of getting exactly 3 heads is     

• 1/ 256 
• 3 /32
• 7/ 32
• 5/ 32

Eight coins are tossed together. The probability of getting exactly 3 heads is     

• 1/ 256 
• 3 /32
• 7/ 32
• 5/ 32

From a pack of 52 cards, two cards are drawn together, what is the probability that both the cards are kings  

• 2/121
• 1/221
• 2/221
• 1/169

A speaks truth in 75% of cases and B in 80% of cases. In what percentage of cases are they likely to contradict each other, narrating the same incident   

• 30%
• 40%
• 45%
• 35%

A box contains 5 green, 4 yellow and 3 white balls. Three balls are drawn at random. What is the probability that they are of same colour.  

• 52/55
•  3/55
•   41/44 
•  3/44

A box contains 20 electric bulbs, out of which 4 are defective. Two bulbs are chosen at random from this box. The probability that at least one of these is defective is  

• 7/19
• 6/19
• 5/19
• 4/19