On a hot afternoon, Scrooge the miser and his grandson, Tim, were walking home from a party.
Tim complains, "Gramps, it's still a long way back to our house. It's hot and I'm tired. Look, there's a bus stop here. Can we please take the bus home?"
Scrooge is aghast. "It'll cost us six dollars to get home from here! What a waste of money! We'll walk it."
Tim sighs, but he's a good kid, and doesn't fuss about it. They barely walk a few feet, when Scrooge sees a passing taxi and hails it.
"How much would you charge to take us home to Springfield Avenue?", Scrooge asks the cab driver.
"Springfield Avenue? Around twenty bucks.", says the driver.
"Oof! That's too much. We won't be requiring your services, thank you."
The cab drives off. Tim turns to his grandfather, exasperated. "Did you *really* think that a taxi to Springfield Avenue would cost less than a bus ride?", he asks, incredulously.
"Don't be ridiculous, of course not.", Scrooge scoffs.
"Then why did you bother flagging down the taxi, Gramps?!"
"Foolish boy! We would've saved $6 by not taking the bus, now we're saving $20 by not taking the taxi!"