TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a woman swinging a tennis racquet towards a tennis ball'. Find frequency of the letter 'e'

SOLUTION: 3

PROBLEM: Sentence: 'a woman in yellow dress standing next to a horse'. Find frequency of the letter 'l'

SOLUTION: 2

PROBLEM: Sentence: 'a flower that is in a glass vase'. Find frequency of the letter 'i'

SOLUTION:
2