Answer: After t seconds, Fred is far away from Mark by (45-t).
Explanation:
Given: Mark gives Fred a 45meter head start.
After t seconds, the distance of Fred from the starting point = 5t+45
The distance of Mark from the starting point = 6t
Now, Distance between Fred and Mark after t seconds = Location of Fred - Location of Mark
= (5t+45)-6t
= 5t+45-6t
= 45-t
Hence, After t seconds, Fred is far away from Mark by (45-t).