NTA Abhyas JEE Main2020MathematicsProbabilityPractice
Out of 1000 boys in a school, 300 played cricket, 380 played hockey and 420 played basketball. Of the total, 120 played both basketball and hockey, 100 played cricket and basketball, 70 played cricket and hockey and 56 played all the three games. If the probability of the number of boys who did not play any game is k , then 200 k is equal to
Correct answer
26.8
Step-by-step solution
n C = 300 , n H = 380 , n B = 42 0 n H ∩ B = 120 , n B ∩ C = 10 0 n H ∩ C = 70 , n C ∩ H ∩ B = 5 6 n C c ∩ H c ∩ B c = n C ∪ H ∪ B c = n U - n C ∪ H ∪ B = 1000 - [ n ( c ) + n ( H ) + n ( B ) - n H ∩ C - n H ∩ B - n C ∩ B + n C C ∩ H ∩ B = 1000 - 300 + 380 + 420 - 120 - 100 - 70 + 56 = 134 Required probability = 134 1000