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

[Q]: Sentence: 'a large motorcycle that has a man dressed in old clothing next to it'. Find frequency of the letter 'a'
[A]: 6

[Q]: Sentence: 'a young boy bouncing a tennis ball on a tennis racquet'. Find frequency of the letter 'a'
[A]: 5

[Q]: Sentence: 'a bearded man takes a bite of cheese pizza off a paper plate'. Find frequency of the letter 'd'
[A]:
2