imane81 wrote:Your input is much appreciated in this one...thank you
Tom reads at an average speed of 30 pages per hour while Jason reads at an average speed of 40 pages per hour. If Tom starts at 4:30 and Jason at 5:20, at what time will they be reading the same page?
Here's a key rule for this type of question:
if two objects are travelling in the same direction, to find the relative rate, SUBTRACT the rates;
if two objects are travelling in opposite directions, to find the total rate, ADD the rates.
In this question, Tom and Jason are travelling in the same direction (i.e. both reading the book starting on the same page and moving toward the end of the book), so we SUBTRACT to get the relative rates.
40-30 = 10,
so Jason catches up 10 pages every hour.
Now that we have the rate, we can calculate the distance Jason needs to cover to catch up:
Tom has been reading for 50 minutes; 30 p/h is .5 p/m, so .5(50) = 25 pages.
time = distance/rate, so:
time to catch up = distance to catch up / rate of catching up
t = 25/10 = 2.5 hours
Tom starts at 5:20, so 5:20 + 2:30 = 7:50 for our catch up moment.
The other approaches posted certainly work (and if you see them may even be faster), but you can use the approach here to reason your way through any similar question.
