Question

a box contains 20 ball bearing number 1,2,3,4.....,20. a ball is drawn at random from the box. what is the probability of getting i] an odd number,ii] a number not divisble by 10,iii] a multiple of 4, iv] a number divisble by 2 and 3

Answer 1

1. p(odd no.) = 10/20= 1/2.
2.p(no. not divisible by 10)= 18/20= 9/10.
3.p( multiple of 4) =5/20 =1/4.
4.p( no. divisible by 2&3).= 12/20=3/4.

Answer 2

1)10/20=1/2
2)18/20=9/10
3)15/20=3/4
4)17/20