Question 288659
Let x = time for both together to finish the task.

{{{(1/4) + (1/6) = (1/x)}}}
LCD for these fractions:  24x
{{{6x + 4x = 24}}}
{{{10x = 24}}}
{{{x = (24/10)}}}
{{{x = (12/5)}}} or 2 hours 24 minutes.