Answer
Tyler to do the job alone =18/1 = 18 hrs
Solution
It takes Tyler twice as long as Kyle to complete the same job.
efficiency of Kyle is twice the efficiency of Tyler
Let x be the efficiency of Tyler the efficiency of Kyle is 2x
efficiency of Tyler : efficiency of Tyler = x :2x =1:2
Therefore total efficiency = 1 + 2 =3x
The total job = efficiency x total time
Here total time to complete the job=6 hrs
Total job =18
Time taken to complete the job =Total job/efficiency
Tyler to do the job alone =18/1 = 18 hrs
Kyle to do the job alone =18/2 = 9 hrs