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

[EX Q]: Sentence: 'a couple of items that are on the wall'. Find frequency of the letter 'm'
[EX A]: 1

[EX Q]: Sentence: 'the receipts from a meal at a restaurant are for  a sandwich, chili, and apple'. Find frequency of the letter 'u'
[EX A]: 1

[EX Q]: Sentence: 'a man holding holding a tennis racquet on a tennis court'. Find frequency of the letter 't'
[EX A]:
4