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

Sentence: 'three young people goofing around; one of the guys has a football, the girl has a teddy bear'. Find frequency of the letter 'd'
3

Sentence: 'an old boat on a beach near a large body of water'. Find frequency of the letter 'a'
8

Sentence: 'a laptop on a desk close to a computer monitor'. Find frequency of the letter 'u'

1