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

[EX Q]: Sentence: 'food sitting in bowls on table with checked tablecloth'. Find frequency of the letter 't'
[EX A]: 6

[EX Q]: Sentence: 'a man riding his skateboard down low as he turns'. Find frequency of the letter 'g'
[EX A]: 1

[EX Q]: Sentence: 'is this polar bear going to jump down into the water'. Find frequency of the letter 'a'
[EX A]:
3