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

[Q]: Sentence: 'a knife a cutting board some bananas and a toaster'. Find frequency of the letter 'i'
[A]: 2


[Q]: Sentence: 'a couple of men sitting next to each other under an umbrella'. Find frequency of the letter 'n'
[A]: 5


[Q]: Sentence: 'a man riding a skateboard on top of a cement ramp'. Find frequency of the letter 'o'
[A]:
4