Edgar was excited when his new car's odometer showed 15,951 miles.

"Wow, a palindrome. That must be rare," he thought.

To his surprised, a new palindrome appeared just two hours later.

What was that number? How fast was Edgar driving?

You have this iron horseshoe. You are also a talented machinist.

1. Can you cut this horseshoe into 6 different pieces, using two straight cuts, without repositioning the workpieces?
2. Can you cut this horseshoe into 6 different pieces - each piece with a hole - using two straight cuts? Yes, you can reposition the workpieces.
Answer, updated 10.22.26
@Rixter gets it in comments No. 1 and 2.

How many lines are there in these pictures? Explain the phenomenon depicted. (Apologies for the freehand Sharpie!)

Figure 1

Figure 2

Answer, updated 9.25.26
Rixter gets in in #1 below.

Use the three white pieces to place the black king (e5) in checkmate.

• You do not need to simulate moves to arrive here.
• Abide standard chess piece movements.
• King can move one space in any direction, but never into check
• Rooks can move any number of spaces, but only vertically or horizontally
• Knights move in an L shape: two spaces vertical or horizontal, plus one perpendicular space
  

Answer, 8.24.26
Deefburger gets it below, #10.

Your friend makes a $250 bet with you.

He will pick a number between 1 and 1,000. If you can guess this number in 10 or less questions or guesses, you win.

Expressed as a percent, what are your odds of winning the $250?
Answer, updated 7.28.26
SilvCrow gets it - answer #2 below.