Let A=(x,y):2x+3y=23,x,y N and B=x:(x,y) A.

Question

Let $A={(x,y):2x+3y=23,x,y\in N}$ and $B={x:(x,y)\in A}$. Then the number of one-one functions from $A$ to $B$ is equal to \_\_\_\_\_\_\_\_\_.

Answer: 24

Accepted Answer

$\begin{gathered} A={(x,y);2x+3y=23,x,y\in N} \ A={(1,7),(4,5),(7,3),(10,1)} \ B={x:(x,y)\in A} \ B={1,4,7,10} \end{gathered}$

So, total number of one-one functions from A to B is $4!=24$

Solutions · 1