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

Sentence: 'a lady mixes some things in a blender as people look on'. Find frequency of the letter 'i'
3

Sentence: 'small black bird with red on its head standing on a tree branch'. Find frequency of the letter 'b'
3

Sentence: 'a grapefruit, toast, coffee and other items are on a tray'. Find frequency of the letter 't'

6