If Felix were to have $100 and writes a check for $150 wouldn't that mean that he has insufficient funds? He has $100 if he writes a check to someone he would not have any money left. He would have -$50.
Alina has $40 when she leaves and she comes back with $40, the question states that there is a change but there is none. She left and came back with the same exact amount of money. Nothing changed.
If Lucas has no money, does some chores, and earns $5, then he would have $5. You didn't complete the question so I will not answer any further.
