TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a girl hitting a tennis ball on a court'. Find frequency of the letter 'l'

SOLUTION: 3

PROBLEM: Sentence: 'a couple of girls are hanging out at a restaurant'. Find frequency of the letter 'l'

SOLUTION: 2

PROBLEM: Sentence: 'a person jumping up into the air on a skateboard'. Find frequency of the letter 'i'

SOLUTION:
3