Hardest brain teasers

how many planes are in the sky atm.

How many diapers are used every year in Wyoming.

I don't think the above brain teasers are that hard, as it does not have a definite correct answer and any solution that you come up with may be as good as the next one.

What makes this number unique -- 8,549,176,320?

Two people are playing a game:

• The first person to roll a 4 on a standard dice wins the game
• If player 1 (who goes first) rolls a 4 on his first roll then the game is over instantly
• If not, player 2 rolls. If player 2 gets a 4 the game is over. If player 2 doesn't roll a 4 the game continues until someone does

Q1 - Does player 1 have an advantage by going first? Q2 - What are the exact odds of player 1 winning the game?

Hint: Answer q2 with a fraction, making a grid of outcomes can help with this brainteaser