human
A man drives 60 mph for 3 hours. How fast would he have to drive over the next 2 hours to get an average speed of 70 mph?
assistant
How many miles does he need to travel? ** To have an average speed of 70 mph over 5 hours he needs to travel 70*5=<<70*5=350>>350 miles.
How many miles did he drive in the first 3 hours? ** He drove 60*3=<<60*3=180>>180 miles in the first 3 hours
How many miles does he need to travel over the next 2 hours? ** He needs to travel another 350-180=<<350-180=170>>170 miles over the next 2 hours.
How fast does he need to drive over the next 2 hours? ** His speed needs to be 170/2=<<170/2=85>>85 mph
#### 85