Answer: $285
Explanation:
First and foremost, we should note that from January 1 to April 1 is 3 months. Since Mario had a savings account balance of $2742 on January 1 and by April 1, his balance had increased to $3597. The increase in balance will be:
= $3597 - $2742
= $855
Then the average savings rate will be:
= Total amount saved / Number of months
= $855/3
= $285
He had an average savings of $285 per month.