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

Q: Sentence: 'two persons standing outside a moving sub train'. Find frequency of the letter 'a'

A: 3
****
Q: Sentence: 'a baseball player dropping his bat and starting to run'. Find frequency of the letter 'o'

A: 2
****
Q: Sentence: 'a very old lady holding a cake by a cute small girl'. Find frequency of the letter 'a'

A:
6
****