Tom is saving $3000. He deposits $200, then a fixed amount every month for 5 months. Then gets a check for 3 times the total amount saved so far. When depositing the check, he now has $400 extra. What was the fixed amount deposited each month?

$280 would be equivilant to $4800. I need the total to equal $3400. It must be a smaller amount than $200 to make sense. Do you know how to set up the problem, or do I need to ask someone else?