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

Sentence: 'a glass bowl of raw broccoli, a ceramic bowl of raw green chili peppers, and steel bowl of raw daikon'. Find frequency of the letter 'a'
9

Sentence: 'a glass a rope and a pair of scissors'. Find frequency of the letter 's'
6

Sentence: 'a couple of elephants are standing in the water'. Find frequency of the letter 'p'

2