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

Sentence: 'one woman is arranging the other woman's hair'. Find frequency of the letter 'o'
4

Sentence: 'a gourmet looking hamburger with fries on a dining table with some wine'. Find frequency of the letter 't'
4

Sentence: 'a herd of cattle walking around on a beach'. Find frequency of the letter 'n'

3