Join the growing community of curious minds on IDNLearn.com. Discover prompt and accurate answers from our experts, ensuring you get the information you need quickly.

Work out the speed in miles per hour at which colin drives home

Work Out The Speed In Miles Per Hour At Which Colin Drives Home class=

Sagot :

Answer:

  20 miles per hour

Step-by-step explanation:

The graph shows it takes Colin 45 minutes (3/4 hour) to drive home. For a given distance (the distance from home to market), the speed is inversely proportional to the time.

The time driving home is (3/4 hour)/(2/4 hour) = 3/2 times the time driving to the market. The inverse of this is 2/3, so Colin's speed driving home is ...

  (2/3)(30 mph) = 20 mph

The speed at which Colin drives home is 20 miles per hour.

_____

Alternate solution

The distance to the market is ...

  distance = speed × time

  distance = (30 mi/h)(1/2 h) = 15 mi

The speed going home is ...

  speed = distance/time

  speed = (15 mi)/(3/4 h) = (15)(4/3) mi/h = 20 mi/h