>27} ‌={n∈S:n<2‌ or ‌n>25} ‌={1,26,27,...,50} ‌⇒‌‌n(A)=26 ‌B={n∈S:n‌ is a prime ‌} ‌={2,3,5,7,11,13,17,19,23,29‌, ‌ ‌31,37,41,43,47} ‌⇒‌‌n(B)=15 ‌C={n∈S:n‌ is a square ‌} ‌={1,4,9,16,25,36,49} ‌⇒‌‌n(C)=7 ‌∴‌‌P(A)=‌