Solution
Given : 9 different colours tulip
white - 1, yellow = 1, pink = 1
(1) Yellow is 1 st in the row
favourable outcome = 1
Total outcome = 9

(2) White is 2nd in the row
favourable outcomes = 1
Total outcomes = (9-1) = 8

2) Pink is at the end in the row
favourable outcomes = 1
Total outcomes = (9-2) = 7

Probability that all 3 are in position

Hence the probability that all three are in position = 1/504