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

Sentence: 'two people wearing snowboards sitting on a snowy slope'. Find frequency of the letter 's'
5

Sentence: 'two little girls playing with a bat and a tennis ball'. Find frequency of the letter 'w'
2

Sentence: 'a double decker bus outside high street shops in the early evening'. Find frequency of the letter 'i'

4