In this task, you need to count the number of times the given letter appears in the given sentence.

Sentence: 'a softball player holding the bat on first base'. Find frequency of the letter 't'
4

Sentence: 'a baby elephant walks beside an adult elephant along a post and cable'. Find frequency of the letter 'l'
6

Sentence: 'group of mixed fruits sitting inside a metal basket'. Find frequency of the letter 'i'
6