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

Sentence: 'a black horse with a white dot on its forehead'. Find frequency of the letter 't'
4

Sentence: 'people plating cake in an office meeting room'. Find frequency of the letter 'g'
2

Sentence: 'a bird with a long narrow beak and a craned neck'. Find frequency of the letter 'i'

2