Probability in poker

Question

In his book "The poker face of Wall Street", A.Brown wrote this:

"If two hands have two different cards ten or higher, there is a 62% chance they share a card of the same rank.

If two hands are pairs or suited connectors, there is only a 7% probability they share a card of the same rank.

If they are both suited hands, there is only a 19% chance they share the same suit."

How did he find these numbers?

Answer 1

One question at a time

Using combinations

One hand is suited

How many other suited hands of that suit
11c2 = 55

How many suited hands not of the suit
13c2 * 3 = 234

Chance of same = 55 / (55 + 234) = 19%

I don't get the purpose those stats.
I cannot think when I would use any of them.