Multiple choice general knowledge math & puzzles

Two cards are drawn from a pack of 52 cards. What is the probability that either both are red both are king?

  1. 7/13

  2. 2/26

  3. 63/221

  4. 55/221

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Use inclusion-exclusion: P(both red) + P(both kings) - P(both red kings). P(both red) = 26C2/52C2 = 325/1326. P(both kings) = 4C2/52C2 = 6/1326. P(both red kings) = 2C2/52C2 = 1/1326. Total = (325+6-1)/1326 = 330/1326 = 55/221.