Second Heads | PuzzledQuant

New on YouTube: This HRT Quant Interview Question Has a One-Line Answer - Watch now

Get quant-ready in 2026

⚡ Build the skills to land top-paying quant jobs. Offer ends in 25d 09h 49m 32s25 days 9 hours 49 minutes 32 seconds.

New on YouTube: This HRT Quant Interview Question Has a One-Line Answer - Watch now

Get quant-ready in 2026

⚡ Build the skills to land top-paying quant jobs. Offer ends in 25d 09h 49m 32s25 days 9 hours 49 minutes 32 seconds.

A bag has three indistinguishable coins, but they have different probabilities of landing heads:

Coin 1: 20%
Coin 2: 20%
Coin 3: 60%

You draw a coin uniformly at random from the bag and flip it; it comes up heads. You flip the same coin again. What is the probability that it comes up heads again? Give the answer as an exact fraction or decimal.

A bag has three indistinguishable coins, but they have different probabilities of landing heads:

Coin 1: 20%
Coin 2: 20%
Coin 3: 60%