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

Sentence: 'a row of vintage cars in a grassy field'. Find frequency of the letter 'v'
1

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

Sentence: 'the gourmet pizza is done and ready to be eaten'. Find frequency of the letter 's'
1