Multiple choice general knowledge math & puzzles

From a 5 different green balls,4 different blue ball and 3 different red balls,how many combinations of ball can be chosen taking atleast one green and one blue ball?

  1. 3780

  2. 3760

  3. 3740

  4. 3720

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

Total ways to choose any subset from 12 balls = 2^12 = 4096. Subtract selections with no green (2^7 = 128) and no blue (2^8 = 256). Add back selections with neither (2^3 = 8) since counted twice. 4096 - 128 - 256 + 8 = 3720.