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

Problem: in how many ways can 21 books on english and 19 books on hindi be placed in a row on a shelf so that two books on hindi may not be together ? 
Options: a ) 1540 , b ) 2314 , c ) 5420 , d ) 1240 , e ) 4512
a

Problem: 3.00001 unbiased coins are tossed . what is the probability of getting 2 tails ? 
Options: a ) 3 / 4 , b ) 1 / 4 , c ) 3 / 8 , d ) 7 / 8 , e ) 1 / 8
c

Problem: two cards are drawn together from a pack of 52 cards . the probability that one is a club and other is a diamond , is : 
Options: a ) 29 / 34 , b ) 47 / 100 , c ) 3 / 20 , d ) 13 / 102 , e ) none of these

d