TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a boy is sitting at a dinner table with his food'. Replace the letter 't' with 'r' in the sentence.

SOLUTION: a boy is sirring ar a dinner rable wirh his food

PROBLEM: Sentence: 'a cat is watching a computer with a video of a cat'. Replace the letter 't' with 'a' in the sentence.

SOLUTION: a caa is waaching a compuaer wiah a video of a caa

PROBLEM: Sentence: 'a cup of coffee and a donut in the box'. Replace the letter 'o' with 'j' in the sentence.

SOLUTION:
a cup jf cjffee and a djnut in the bjx