In this task, you need to count the number of times the given letter appears in the given sentence.

Q: Sentence: 'a picture of a machine built next to a street'. Find frequency of the letter 'x'

A: 1
****
Q: Sentence: 'the two dogs are playing in the pen together'. Find frequency of the letter 'o'

A: 3
****
Q: Sentence: 'a woman stands in a living room playing an interactive video game'. Find frequency of the letter 'a'

A:
8
****