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

Sentence: 'man riding a skate board down the little board way'. Find frequency of the letter 'k'
1

Sentence: 'wooden and black bench on the side of the road'. Find frequency of the letter 'a'
3

Sentence: 'a couple cutting their wedding cake together with one knife'. Find frequency of the letter 'e'
8