Mr. Maxwell takes 1 hr to drive to work in the morning but 1 and half hours to drive back home in the evening. If the morning and evening traffic is similar and he drives at an average speed of 30mph in the morning, what is the average speed of his return journey?
In the morning he travels at an average speed of 30mph for 1 hour so he covers a distance of 30*1 = <<30*1=30>>30 miles
He covers the same distance of 30 miles in the evening spending 1.5 hours so his average speed must be 30/1.5 = <<30/1.5=20>>20mph
#### 20