Franklin lent Darlene as much money as she already had, then she spent $10. The next day, Franklin lent her as much money as she now had and again, she spent $10. On the third day Franklin once again lent her as much money as she now had and she spent $10, leaving her broke. How much money did Darlene start with?
$8.75 You may have been tempted to guess $30 because $10 is spent three times, but that would mean she would have had $60 ($30 lent plus the $30 she already had), and $50 after spending $10. The rest of the numbers end up at higher than zero, so we know it has to be less than $30. Even starting at $10 leaves Darlene with $10 on the third day. Starting with $8.75 works out as follows.
Wesley’s mom discovered a broken window in the living room and went to ask Wesley about it. Wesley told her he had been playing Monopoly with his friend Cindy. She asked him what his last roll had been and he said, “A one”. She immediately knew he was lying.
Monopoly has two dice, and the lowest number two dice can roll is 2. The window repair came out of Wesley’s allowance and he stopped throwing his baseball in the house.
A variation of this brain teaser includes laser printers (they were invented by Gary Starkweather) and bulletproof vests (invented by Casimir Zeglen using silk, though modern vests use Kevlar, so it’s halfway right).
I go up, but at the same time go down, Up toward the sky and down toward the ground, I’m present tense and past tense too, Come for a ride, just me and you.
