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

Sentence: 'a  woman standing next to a man on a motorcycle in front of a market'. Find frequency of the letter 'l'
1

Sentence: 'small airplane in the process of taking off'. Find frequency of the letter 'e'
3

Sentence: 'a train on a rail line near some trees'. Find frequency of the letter 'e'

5