Question

Hello! I'm having troubles with the word problem i've stumbled upon.

A cyclist is travelling six times as fast as a
pedestrian. The difference in their speeds is
17.5 km/h. What is the cyclist’s speed?

and

During a camping trip, Nina was making a
lean-to for sleeping. She cut a 2.5-m long
post into two pieces, so that one piece was
26 cm longer than the other. What was the
length of each piece?

Thank you very much!