A man goes into a store and says to the owner: "Give me as much money as I have with me and I will spend $10."
It is done and the man repeats the operation at a second and a third store, after which he has no money left.
How much did he start with?
Solution:
The answer is $8.75
Let x = how much the man started with.
Then in the first store:
x + x - 10 is how much he had left.
In the second store:
(2x-10) + (2x-10) - 10 is how much is left
This simplifies to 4x - 30
In the third store:
(4x-30) + (4x-30) - 10 is how much is left
This simplifies to 8x - 70
So, 8x - 70 = 0 (no money left)
8x = 70
x = 70/8 or $8.75
Correctly solved by:
| 1. Richard Mocarski | Winchester, VA |
| 2. Chip Crawford | Winchester, VA |
| 3. Sam Stiebel | Winchester, VA |
| 4. Kirstine Wynn | Winchester, VA |
| 5. Elizabeth Cotter | Oak Hill, VA |
| 6. Tom Marino | Winchester, VA |
| 7. Court Pifer | Winchester, VA |
| 8. Joe Jenkins | Winchester, VA |
| 9. Eric Harding | McLean, VA |
| 10. Zinedine Zindane | Marseille, France |
| 11. John Pence | Winchester, VA |
| 12. Ryan Throckmorton | Winchester, VA |