Hello, Felipe!

What is the chance that the 7th card from the top of the deck will be a heart?

The deck can be arranged in orderings.

If the 7th card is a Heart, there are 13 choices.

The other 51 cards can be arranged in ways.

. . Hence, there are: orderings with the 7th card a Heart.

Therefore: .

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

With a little Thought, the answer is obvious.

Considercard in the deck,any

. . the top card, the bottom card, the 37th card . . .

What is the probabiity that it is a Heart?

Since it could any one of the four suits (all equally likely),

. .