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

Sentence: 'a gourmet looking hamburger with fries on a dining table with some wine'. Find frequency of the letter 't'
4

Sentence: 'person wearing all white leaned up against a wall with a yellow sign'. Find frequency of the letter 'a'
8

Sentence: 'a clean kitchen with stainless steel cabinets and a stove filled with pans'. Find frequency of the letter 'v'
1