mark reads at an average of 30 pages per hour, 
while mindy reads an average of 40 pages per 
hour. if mark starts reading a novel at 4:30 
pm and mindy starts reading the same novel 
5:20 pm, what time will they be reading on the 
same page?

Here is a problem that has exactly the same answer:

Mark rides his lightweight motorcycle at 
30 miles per hour, while Mindy rides her 
lightweight motorcycle at 40 miles per hour.  
If mark start out at 4:30 pm and Mindy starts 
out on the same road from the same starting 
point at 5:20 pm, what time will Mindy catch 
up with Mark?

Make this chart:

         Distance   Rate   Time   
Mark                                          
Mindy                         

Let t = the number of hours after 4:30 when 
Mindy catches Mark. So fill in t as Mark's time, 
since he started at 4:30

         Distance   Rate   Time   
Mark                         t
Mindy                            

Fill in their rates of 30 mph and 40 mph

         Distance   Rate   Time   
Mark                 30      t
Mindy                40           

Now Mindy did not travel as long as Mark. It
is 50 minutes from 4:30 to 5:20, 50 minutes
is 50/60 or 5/6 of an hour, so her time is
5/6 less than Mark's or t-5/6. So fill that
in for Mindy's time:

         Distance   Rate   Time   
Mark                 30      t
Mindy                40    t-

Now fill in the distances using D = RT

         Distance   Rate   Time   
Mark       30t       30      t
Mindy    40(t-)   40    t-


Mindy catches Mark when their
distances are equal. So the equation
is

   30t = 40(t-)

Can you solve that? If not post again 
asking how.

Solution: 10/3 hr. or 3 hours or 
3 hours 20 minutes.   

Answer to problem: 3 hours 20 minutes after
4:30PM is 7:50PM 

That's the same answer as for the book reading.

Edwin