Probability related Questions by Balaji

[Balaji]

N is a three digit no  that is multiple of 7 what is the prob that it will be multiple of 5


a) 1/5


b) 11/54


c) 13/64


d) 13/66

answer choice c







solution







there are 26 such numbers so







probability = 26/128



=13/64

 

[Balaji]

consider a 3 digits number abc. what is the probability that a>b>c ?



a) 1/12



b) 1/6



c) 2/15



d) 1/7

answer choice d



solution



denominator = total no of 3 digit no = 9*10*10

=900



required probability = 84+36/900=120/900=2/15


 

[Balaji]

An unbiased coin is tossed 16 times what is the probability of getting more heads than tails ?



a) 26333/65536



b) 26333/32768



c) 1/2



d) 26283/65536

answer choice  a



solution



prob (more heads than tails) = (1- 16c8*(0.5)*16)/2

=26333/65536