In this task, you need to provide the correct option for a given problem on probability from the provided options.

[EX Q]: Problem: a question paper has 2 parts , a & b , each containing 5 questions . if a student has to choose 3 from part a & 4 from part b , in how many ways can he choose the questions ? 
Options: a ) 50 , b ) 100 , c ) 152 , d ) 150 , e ) 55
[EX A]: a

[EX Q]: Problem: a box contains 100 balls , numbered from 1 to 100 . if 3 balls are selected at random and with replacement from the box . if the 3 numbers on the balls selected contain two odd and one even . what is the probability j that the first ball picked up is odd numbered ? 
Options: a ) 0 , b ) 1 / 3 , c ) 1 / 2 , d ) 2 / 3 , e ) 1
[EX A]: d

[EX Q]: Problem: two coins are tossed . find the probability of at most 2 tails ? 
Options: a ) 1 / 2 , b ) 1 / 4 , c ) 1 / 3 , d ) 1 , e ) 3 / 4
[EX A]:
d