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

Q: Sentence: 'some giraffes moving across a big grass field'. Find frequency of the letter 'e'

A: 3
****
Q: Sentence: 'a red fire hydrant opened and spilling water'. Find frequency of the letter 'd'

A: 4
****
Q: Sentence: 'people walking through a busy airport carrying luggage'. Find frequency of the letter 'u'

A:
3
****