Q.

Let A={(x,y):2x+3y=23,x,y∈N} and B={x:(x,y)∈A}. Then the number of one-one functions from A to B is equal to ________ .        [2024]


Ans.

(24)

    We have, A={(x,y):2x+3y=23,x,y∈N}

   B={x:(x,y)∈A}

  ∴A={(1,7),(4,5),(7,3),(10,1)}

   and B={1,4,7,10}

   Total number of one-one functions from A to B = 4! = 24