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

Sentence: 'a group of men standing around a table cutting a cake'. Find frequency of the letter 'g'
3

Sentence: 'seagulls sit on the posts of a seaside balcony by a clock tower'. Find frequency of the letter 'g'
1

Sentence: 'a zebra lying in the sand in the sun'. Find frequency of the letter 'n'

5