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

Sentence: 'a street scene looking at the back of the stop sign'. Find frequency of the letter 't'
6

Sentence: 'bathroom scene with a black cat going behind the door'. Find frequency of the letter 'e'
4

Sentence: 'a man is flying a kite on the beach'. Find frequency of the letter 'o'

1