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

Sentence: 'the interior of a living and dining room'. Find frequency of the letter 'i'
6

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

Sentence: 'a group of cars and house on truck passing in a street'. Find frequency of the letter 'i'

2