(4 points) If

f:A->B

is a function such that

B={f(x):xinA}

, then we call

f

"Alkong".\ How many Alkongs are there if

|A|=a

and

|B|=b

.\ Use inclusion exclusion formula

5. (4 points) If f:AB is a function such that B={f(x):xA}, then we call f "Alkong". How many Alkongs are there if A=a and B=b