TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a table topped with a cupcake on a picture of a cupcake'. Find frequency of the letter 'o'

SOLUTION: 3

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

SOLUTION: 1

PROBLEM: Sentence: 'sheep graze along a wooden fence as a photographer studies them from a stairway'. Find frequency of the letter 'n'

SOLUTION:
3