Answer:
24 hours
Step-by-step explanation:
The computation of the number of hours taken by Bobby to build the robot by himself is shown below:
Given that
Bobby could take 12 hours
Together they could build in 8 hours
So based on the above information
the number of hours taken by Bobby to build the robot by himself is
Let us assume the above line be x
So,
[tex]\frac{1}{8}-\frac{1}{12} = \frac{1}{x} \\\\\frac{6 - 4}{48} = \frac{1}{x} \\\\\frac{2}{48} = \frac{1}{x} \\\\x = \frac{48}{2}[/tex]
x = 24 hours
