A cyclist traveled 9 kilometers per hour faster than an in-line skater. In the time it took the cyclist to travel 45 kilometers, the skater had gone 30 kilometers. What's the speed of the skater?

Therefore, the speed of the skater is 6 kilometers per hour.

Step-by-step explanation:

speed of the skater as in kilometers per hour = x

speed of the cyclist = x + 9

45 / (x + 9) = 30 / (x)

45x = 30x + 270

45x - 30x = 270

15x = 270

x = 270/15

x = 18

x + 9 = 18

x = 18 - 9

x = 9

9/45 = x/30

45x = 270

x = 270/45

x = 6

Therefore, the speed of the skater is 6 kilometers per hour.