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

Q: Sentence: 'a double decker transit bus parks by a blue on the side of the street in front of a brick building in the city'. Find frequency of the letter 't'

A: 9
****
Q: Sentence: 'a girl hitting a tennis ball on a court'. Find frequency of the letter 'l'

A: 3
****
Q: Sentence: 'a woman holding a umbrella in her hand'. Find frequency of the letter 'n'

A:
4
****