First part of the question
A bank was robbed this morning. A lone robber carried the loot away in a big leather bag. The manager of the bank said that the money stolen consisted of small bills: \$5, \$10, and \$20. Throughout the day, some news stations have reported that the robber stole approximately \$1,000,000 in small bills, but Becky, a senior investigative reporter at Channel 10 News, thinks this is more money than one person could carry.
Becky wants to know how hard it would be for one person to carry \$1,000,000 in small bills. Investigate this question to determine if it is possible.
Second part of the question
Becky knows that she will have to investigate and report on other bank robberies in the future. In other robberies, the money stolen might not consist only of small bills. For example, it might consist \$50 and \$100 bills, or only \$100 bills, or some combination of \$5, \$10, \$20, \$50 and \$100 bills. Becky would like to be able to prepare quickly for her news reports without having to ask you for help each time a bank is robbed.
Describe a general method for her to use in preparing for future bank robbery reports (using appropriate algebraic expressions) for figuring out whether or not a person could carry any amount of money, using any combination of bills.
I know that I should start with the second part of the question in order to work out the first, but I am unsure of which direction to take. Any suggestions would be much appreciated, thank you!