TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'the bathroom is in need of remodel'. Find frequency of the letter 'e'

SOLUTION: 5

PROBLEM: Sentence: 'two people under an umbrella while walking down a sidewalk'. Find frequency of the letter 'i'

SOLUTION: 3

PROBLEM: Sentence: 'a woman is getting ready to hit a ball with a tennis racket'. Find frequency of the letter 'h'

SOLUTION:
2