College Algebra (6th Edition)

$\log_{3}40$ is greater.
$60$ is a number between $4^{2}=16$ and $4^{3}=64$, so $\log_{4}60$ is a number between 2 and 3. $40$ is a number between $3^{3}=27$ and $3^{4}=81$ so $\log_{3}40$is a number between 3 and 4. Thus, $\log_{3}40$ is greater.