f:A→Bf : A \to Bf:A→B with ∣A∣=5|A|=5∣A∣=5, ∣B∣=2|B|=2∣B∣=2. How many onto functions?
52−15^2 - 152−1
52−25^2 - 252−2
25−12^5 - 125−1
25−22^5 - 225−2
