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

[Q]: Sentence: 'a family sitting at a table in a restaurant looking at their phones'. Find frequency of the letter 't'
[A]: 8


[Q]: Sentence: 'this yellow fire hydrant sits in a grass field'. Find frequency of the letter 'i'
[A]: 5


[Q]: Sentence: 'a snowboarder in camp clothing standing still'. Find frequency of the letter 'd'
[A]:
2