Two mismatched dice

You roll a fair 4040-sided die and a fair 6060-sided die (faces 11 through 4040 and 11 through 6060 respectively). What is the probability that the 6060-sided die shows a strictly greater value than the 4040-sided die? Round to the nearest hundredth.

Show hints (2)+
  1. Condition on the 4040-sided die showing aa; then the 6060-sided die beats it with probability (60−a)/60(60-a)/60.
  2. Average over a=1,…,40a = 1,\dots,40. The relevant sum is 59+58+⋯+2059 + 58 + \dots + 20.

Answer

Reveal answer →

0.66 (± 0.01)

Create a free account to see the full worked solution and track your progress.

Interview format: Numerical Reasoning Tests, Options Trading

Related questions