A bag contains 4 red, 5 yellow or 6 pink balls. Two balls are drawn at random. What is the probability that none of the balls drawn are yellow in colour

Directions (next five questions) : What should come in place of question mark (?) in the following question ?

Directions (next five questions) : In these questions, two equations numbered I and II are given. You have to solve both the equations and mark the appropriate option.