Onto functions

MediumCombinatorics~6m

How many functions from a $5$ -element set onto a $3$ -element set are there?

Show hints (2)+

Subtract functions that miss at least one target.
Inclusion–exclusion: $\sum_k (-1)^k \binom{3}{k}(3-k)^5$ .

Answer

Reveal answer →

150

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

Create a free account

Interview format: Market Maker, Systematic & Data-Driven Trading

Related questions