TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a small boy in a high chair eating a cupcake'. Find frequency of the letter 'i'

SOLUTION: 4

PROBLEM: Sentence: 'a group of giraffes walk together by a hill'. Find frequency of the letter 'b'

SOLUTION: 1

PROBLEM: Sentence: 'a person riding skis on a snowy surface'. Find frequency of the letter 'n'

SOLUTION:
4