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

[EX Q]: Sentence: 'a passenger bus that is driving down the street'. Find frequency of the letter 'r'
[EX A]: 3

[EX Q]: Sentence: 'an audience watches as a bird spreads its wings'. Find frequency of the letter 'd'
[EX A]: 3

[EX Q]: Sentence: 'this tiny vase has a pink flower on it'. Find frequency of the letter 'i'
[EX A]:
4