Question

Shanice left Kali's house and drove toward

the desert at an average speed of 70 km/h.
Lisa left one hour later and drove in the
opposite direction with an average speed of
55 km/h. Find the number of hours Lisa
needs to drive before they are 570 km apart.

Answer 1

Answer: 4 hours

Make a number line and put up to 5 hours going both directions. one direction will be shanice, the other lisa. youll skip an hour for lisa. so shanice will arrive at 350km and lisa will get to 220km at the five hour mark. It’s a lot simpler then doing the actual math.