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

[Q]: Sentence: 'older man getting ready to swing his bat at a ball on a stand in front of a group of viewers'. Find frequency of the letter 'n'
[A]: 7

[Q]: Sentence: 'an commercial airline airplane flies above the clouds'. Find frequency of the letter 'n'
[A]: 3

[Q]: Sentence: 'a bathroom with a view of a toilet and walk in shower with a bench'. Find frequency of the letter 'i'
[A]:
5