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

[Q]: Sentence: 'a line of people on motorcycles on the road'. Find frequency of the letter 'e'
[A]: 5


[Q]: Sentence: 'a man walking a large elephant down a dirt road'. Find frequency of the letter 'g'
[A]: 2


[Q]: Sentence: 'a variety of signs taken in chinatown'. Find frequency of the letter 'o'
[A]:
2