instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a man and several white red and blue airplanes'. Find frequency of the letter 'u'
answer:
1

question:
Sentence: 'a bunch of cows that are in the field'. Find frequency of the letter 'a'
answer:
3

question:
Sentence: 'a piece of carrot cake and cup of coffee are by a keyboard'. Find frequency of the letter 't'
answer:
1