⚡ Build the skills to land top-paying quant jobs. Offer ends in --d --h --m --s-- days -- hours -- minutes -- seconds.
⚡ Build the skills to land top-paying quant jobs. Offer ends in 19d 08h 36m 03s19 days 8 hours 36 minutes 3 seconds.
There are letters and envelopes. Your servant puts the letters randomly in the envelopes so that each letter is in one envelope and all envelopes have exactly one letter. (Effectively a random permutation of n numbers chosen uniformly). Calculate the expected number of envelopes with correct letter inside them.