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

Sentence: 'there is an old stove with old pots on the burners'. Find frequency of the letter 't'
5

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

Sentence: 'a white vase of flowers on the ground'. Find frequency of the letter 'n'

2