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

[Q]: Sentence: 'a bowl of granola, dried fruit, and bananas'. Find frequency of the letter 'u'
[A]: 1


[Q]: Sentence: 'a dog is shown sitting on rocks by the beach'. Find frequency of the letter 'a'
[A]: 2


[Q]: Sentence: 'a couple of people tending to a conveyor belt with lots of donuts on it'. Find frequency of the letter 'r'
[A]:
1