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

Sentence: 'a young girl is brushing her teeth in this dated photo'. Find frequency of the letter 't'
5

Sentence: 'the little girl is flying her kite in the field'. Find frequency of the letter 'i'
7

Sentence: 'a girl holding a tennis racket up with both hands'. Find frequency of the letter 'p'

1