Answer:
3.5 hours
Explanation:
Given: Distance= 26.2 miles
Speed= 12 km/h
First lets convert the unit of speed from kmh to mph.
Remember, 1 mile= 1.609 km
∴ For speed of 12 km/h=

Speed= 7.45 mph
Next, find time taken by Allan to complete a Marathon.

⇒ Time=

∴ Time= 3.516 hours ≅ 3.5 h (nearest tenth)
∴ Allan took 3.5 hours to complete marathon.