Question 18998
<table border=2><tr><td>Data<td>First case<td>Second case
<tr><td>distance<td>300 miles<td>400 miles
<tr><td>speed<td>x mph<td>(x-10)mph
<tr><td>time=distance/speed<td>300/x<td>400/(x-10)
</table>
total travelling time=(300/x)+(400/(x-10))
for x=60,total travelling time is:
=(300/x)+(400/(x-10))
=(300/60)+(400/(60-10))
=(300/60)+(400/50)
=5+8
=13 hours
<P>
Hope this helps,
Prabhat