instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a dog has found a rather large stick for playing fetch'. Find frequency of the letter 't'
answer:
3

question:
Sentence: 'a room with a big screen television and a couch'. Find frequency of the letter 'h'
answer:
2

question:
Sentence: 'a young girl is sitting in front of a birthday cake'. Find frequency of the letter 'y'
answer:
2