Jerry works five days a week as a waiter and earns a variable amount of tips every night. The past four nights, he earned $20, $60, $15, and $40. How much does he need to earn tonight if he wants to make an average of $50 in tips per night? Give me reasons, before answering the question
The total money Jerry needs to make for 5 days to get $50 per night is 5 nights * $50 / night = $250. His total earnings for the past four days is $20 + $60 + $15 + $40 = $135. So, Jerry needs to earn $250 - $135 = $115 in tips tonight. So the final answer is 115.