Choosing the first tile:
At first, there are 7 tiles.
You are interested in choosing a 5. There is only one tile with a 5.
p(5) = 1/7
Choosing the second tile:
After the 5 has been taken, now there are 6 tiles left.
Only one tile has the number 6.
p(6) = 1/6
The overall probability of choosing a 6 after a 5 is the product of the individual probabilities:
p( 5 then 6) = 1/7 * 1/6 = 1/42
Answer: The probability of choosing a 5 and then a 6 is 1/42
:)