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: 'one man grabbing another at a table while laughing'. Find frequency of the letter 'n'
5

Sentence: 'a view of a vase sitting on a blue towel'. Find frequency of the letter 'e'
4