instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a group of workers washing and cleaning fruits and vegetables'. Find frequency of the letter 'i'
answer:
3


question:
Sentence: 'a man and several white red and blue airplanes'. Find frequency of the letter 'u'
answer:
1


question:
Sentence: 'a table with plates of food with cups near back'. Find frequency of the letter 'e'
answer:

3