In this task, you need to count the number of words in a sentence that contain the given letter

Sentence: 'a black sign that is standing in the grass'. How many words contain the letter 'f' in the sentence.
0

Sentence: 'a surfer in a black wet suit riding a wave in the ocean'. How many words contain the letter 'x' in the sentence.
0

Sentence: 'woman in yellow and black plaid ski suit standing with snow board'. How many words contain the letter 's' in the sentence.

4