Question 207884
A motor cyclist makes a trip of 500 km.
 If he had increased his speed by 10 km/h, he could have covered 600 km in the same time. 
What was his original speed?
;
Let s = original speed
then
(s+10) = faster speed
:
Write a time equation: Time {{{dist/speed}}}
:
Original time = faster speed time
{{{500/s}}} = {{{600/(s+10)}}}
Cross multiply
600s = 500(s+10)
:
600s = 500s + 5000
:
600s - 500s = 5000
s = {{{100/5000}}}
s = 50 km/hr original speed
:
:
Check solution by finding the times
500/50 = 10 hrs
600/60 = 10 hrs