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

Q: Sentence: 'a red and white train passing a train station'. Find frequency of the letter 'a'

A: 7
****
Q: Sentence: 'a group of cars and house on truck passing in a street'. Find frequency of the letter 'i'

A: 2
****
Q: Sentence: 'a small cat laying its head across a bicycle'. Find frequency of the letter 'c'

A:
4
****