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

Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'
2

Sentence: 'two giraffes, one standing and one laying down'. Find frequency of the letter 'g'
3

Sentence: 'a bathroom with a mirror, sink and a toilet'. Find frequency of the letter 'o'

4