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

Sentence: 'a bird is standing on the ledge of the building'. Find frequency of the letter 't'
3

Sentence: 'a desk covered in notepads, a laptop and other devices'. Find frequency of the letter 'c'
2

Sentence: 'a road with a car at the end of the road surrounded by trees'. Find frequency of the letter 'd'
5