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

Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'
1

Sentence: 'a jet that is flying in the sky with a banner behind it'. Find frequency of the letter 'r'
1

Sentence: 'an elephant sticking its trunk through a fence'. Find frequency of the letter 'h'

3