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

Sentence: 'old double decker bus parked in a lot'. Find frequency of the letter 't'
1

Sentence: 'a number of small boats on a beach near an umbrella'. Find frequency of the letter 's'
2

Sentence: 'a man and a women who are sitting on a bench together'. Find frequency of the letter 'o'

4