Set S is the prime integers between 0 and 50. If three numbers are chosen randomly from set S, what is the probability that the sum of these three numbers is odd?
Options:
A) 15/56 B) 3/8 C) 15/28 D) 4/5 E) 3/4
Total number of combinations=15C3=455................(1)   Total number of combinations including 2 and two other numbers=14C2=91......................(2)   Therefore the difference ie. (1)-(2) is the set of 3 primes without 2=(455-91)= 
<gadget id="calculator">(455-91)</gadget>
<output>364</output>
364   So, probability=364/455=4/5   4/5
<result>D</result>
Set S is the prime integers between 0 and 50. If three numbers are chosen randomly from set S, what is the probability that the sum of these three numbers is odd?