TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a bird in a tree looking up at branches'. Find frequency of the letter 'e'

SOLUTION: 3

PROBLEM: Sentence: 'a man sitting on a motorcycle near two other men'. Find frequency of the letter 'r'

SOLUTION: 3

PROBLEM: Sentence: 'there is a quilt and some pillows on a bed'. Find frequency of the letter 'w'

SOLUTION:
1