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

[Q]: Sentence: 'a woman in a messy kitchen with a child'. Find frequency of the letter 'a'
[A]: 4

[Q]: Sentence: 'a person on a skateboard going down a ramp'. Find frequency of the letter 'n'
[A]: 4

[Q]: Sentence: 'a breakfast of eggs, avocados and toast on a blue flowered plate'. Find frequency of the letter 'g'
[A]:
2