Question

If $A=(3,81)$ and $f:A\to B$ is a surjection defined by $f[x]={\log }_{3}x$ then $B=$

• A. [1,4]
• B. (1,4]
• C. (1,4)
• D. $[1,\infty )$

Answer 1

Answer: (C)

$3<x<81\Rightarrow {\log }_{3}3<{\log }_{3}x<{\log }_{3}81$