TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'

SOLUTION: 2

PROBLEM: Sentence: 'baseball player reaching back as he's about to throw the ball'. Find frequency of the letter 'e'

SOLUTION: 5

PROBLEM: Sentence: 'an orange and black fire hydrant at the edge of a street'. Find frequency of the letter 'h'

SOLUTION:
2