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

Sentence: 'group of cars on the road with the sun setting behind it'. Find frequency of the letter 'd'
2

Sentence: 'people waiting on a train platform in a wooded area'. Find frequency of the letter 'p'
3

Sentence: 'a dog running in a field with people around'. Find frequency of the letter 'd'

3