Question

What is the average speed that robin mus drive to reach her friend's house 170 miles away in 2 1/2 hr

Answer 1

$v = d \div t$
$v = (170 \: mi \times 1.609 \: km) \div 2.5 \: hrs$
$v = 273.53 \: km \div 2.5 \: hrs$
$v = 109.412 \: kmhr - 1$
The average speed is 109.412 kilometers per hour.

Answer 2

68 miles / hour

Average speed = distance / time

distance = 170 and time = 5/2 ( as an improper fraction)

speed = 170 ÷ $\frac{5}{2}$ = 170 × $\frac{2}{5}$ = $\frac{340}{5}$ = 68