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

Sentence: 'a bird outside standing on a table looking up'. Find frequency of the letter 'b'
2

Sentence: 'slices of orange are arranged on a plate'. Find frequency of the letter 's'
2

Sentence: 'a person riding a camel in front of a truck'. Find frequency of the letter 't'
2