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

[EX Q]: Sentence: 'a woman sitting in front of a giant slice of cheese pizza'. Find frequency of the letter 'e'
[EX A]: 4

[EX Q]: Sentence: 'a glass bowl of raw broccoli, a ceramic bowl of raw green chili peppers, and steel bowl of raw daikon'. Find frequency of the letter 'a'
[EX A]: 9

[EX Q]: Sentence: 'a couple of white toilets sitting inside of stalls'. Find frequency of the letter 'e'
[EX A]:
4