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

Sentence: 'silhouette of person playing frisbee with moutain and sunset'. Find frequency of the letter 'i'
5

Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'
2

Sentence: 'a very tasty looking pasta dish with some greens'. Find frequency of the letter 'a'

4