Question

A bag contains 20 balls. 8 balls are green, 7 are white and 5 are red. What is the minimum number of balls that must be picked up from the bag blindfolded (without replacing any of it) to be assured of picking at least one ball of each colour?

(a) 17

(b) 16

(c) 13

(d) 11

Answer 1

Correct option is (b) 16

Considering the worst case First 15 picked balls are red and white. Hence in 16th time it is assured that 3 different colour balls exist.