Answer:
The correct answer option is 24 min.
Step-by-step explanation:
Let us assume t to be Chris's time (in hours) so we can write the following equation:
Samir's time (in hours) [tex]=t + \frac{12}{60} = t + 0.2[/tex]
Chris's rate [tex](r_1)=9 mph[/tex]
Samir's rate [tex](r_2)=6 mph[/tex]
Then putting the values in the formula to get:
[tex]r_1t = r_2(t + 0.2)[/tex]
[tex]9t = 6(t + 0.2)[/tex]
[tex]9t=6(t+0.2)\\\\9t=6t+1.2\\\\9t-6t=1.2\\\\3t=1.2\\\\t=0.4[/tex]
t = 0.4 which will be [tex]0.4*60=24[/tex]
Therefore, Chris catches up Samir after riding for 24 minutes.