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

[Q]: Sentence: 'a full plate of food that includes rice and broccoli and carrots'. Find frequency of the letter 's'
[A]: 2


[Q]: Sentence: 'a bathroom that has it's lights turned on'. Find frequency of the letter 'h'
[A]: 4


[Q]: Sentence: 'a train is rounding the corner on a track'. Find frequency of the letter 't'
[A]:
3