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

Sentence: 'a young woman dressed in green and black operating a remote control'. Find frequency of the letter 'r'
5

Sentence: 'statues of 2 zebras and 1 giraffe in a doorway'. Find frequency of the letter 'a'
6

Sentence: 'a skier skiing with her poles tucked under her arms'. Find frequency of the letter 'c'
1