probability aptitude tricks - Interview Questions

probability aptitude tricks

Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5 ?

Answer : D. 9/20…

A bag contains 4 black, 5 yellow and 6 green balls. Three balls are drawn at random from the bag. What is the probability that all of them are yellow ?

Answer : A. 2/91

If 56Pr+ 6 : 54Pr + 3 = 30800 : 1 then the value of r is ?

Answer : B. 41