Question

Alex drives at an average speed that is 1/4 of the average speed that Roy's train travels. Alex takes 20 minutes to travel 12 km in her car. Roy travels for 2 hours and 20 minutes on his train. How far does Roy travel to 2 dp?

Answer 1

336 km

Explanation:

"Alex takes 20 minutes to travel 12 km in her car."

Alex's speed = (12 km)/(20 min) = 0.6 km/min

"Alex drives at an average speed that is 1/4 of the average speed that Roy's train travels."

Therefore, Roy's speed is 4 times Alex's speed.

Roy's speed = 4 * 0.6 km/min = 2.4 km/min

Roy travels for 2 hours and 20 minutes = 2 * 60 min + 20 min = 140 min

speed = distance/time

distance = speed * time = 2.4 km/min * 140 min = 336 km

Answer 2

336.00 km distance of train

Explanation:

Alex = 20mins =12km We distribute to 1hr to find 60mins = 36km p/h.

Roy = 2hrs 20 mins and is 4x the speed of the car.

So 36km x 4 p/h = 144km p/h

2hrs and 20 = 144 x 2.3333 = 335.9952 = 336km