Question

Joseph and his family were going to the beach. Joseph's sister was running late so Joseph left their house with his mom. Joseph's dad waited for his sister to get ready and left one hour later driving 75 km/hour in an effort to catch up to Joseph and mom. After

driving for four hours Joseph's dad finally caught up. How fast was Joseph's mom driving?

Select the correct response:
100 km/hour
30 km/hour
60 km/hour
50 km/hour

Answer 1

a solid 50 km/hour

Explanation:

Answer 2

60 km/hr.

Explanation:

When Dad caught up the the time he had been driving was 4 hours and the time Mom had been driving was 1 + 4 = 5 hours.

They both drove the same distance, d km.

For Dad:

speed = d / time

75 = d / 4

d = 75 * 4 = 300 km.

Mom took 5 hours to travel this distance, so

Mom's speed was 300 / 5 = 60 km/hr.

Explanation: