Question 12
Excluding the cue ball (white ball), a complete set of snooker balls consist of 21 balls, of which there are 15 red balls, which are worth 1 point each, and the 6 other non-red balls which are worth 2, 3, 4, 5, 6 and 7 points respectively. Two balls are randomly selected from these 21 balls at the same time. Let $p$ be the probability that the total value of the two balls selected is at most 5 points. What is the value of $210p$?