Question

Susan rode her bike 30 kilometers in 2.5 hour. How fast did she ride her bike in kilometers per hour

Answer 1

The answer is 12. All you had to do was divide. 
So, 30 divided by 2.5 equals 12.
I hope this helps!

Answer 2

Speed= distance : time
= 30 : 2.5
= 12

answer: 12 km/h