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

Sentence: 'two zebra stand near the wooden posts on a building'. Find frequency of the letter 't'
4

Sentence: 'a group of men standing on the side of a boat'. Find frequency of the letter 'o'
5

Sentence: 'a bunch of colorful rectangular boxes at a primary school'. Find frequency of the letter 'a'

6