word problem

[smith04]

It looks lilke the 2 brothers need to cover 200 miles..... combined speed is 100 MPH.... and will take 2 hours to meet up,,,,
Is this correct and is that the proper format for the equation?

Two brothers leave seperate location 200 miles apart at 9 am.....Brother 1 travels at 60MPH Brother 2 travels at 40MPH What time will they meet up?

T = (60MPH + 40 MPH) / 200mi

 

[soroban]

Hello, smith04!

Two brothers leave seperate location 200 miles apart at 9 am.
Brother 1 travels at 60 mph; Brother 2 travels at 40 mph.
What time will they meet up?

T = (60MPH + 40 MPH) / 200mi . . . . no

Did you solve your equation?

You would get: .\(\displaystyle T \:=\:\frac{100}{200} \:=\:\frac{1}{2}\text{ hour}\)

That can't be right . . .
In a half-hour, Brother-1 would travel 30 miles; Brother-2 would travel 20 miles.
. . They would still be 150 miles part.


You began with some correct reasoning, but didn't follow up.

Their combined speed is 100 mph.
It is as if Brother-2 is standing still, and Brother-1 is approaching at 100 mph.

So how long will it take him to travel 200 miles?

 

[smith04]

I wrote it backwards......


T= 200mi/ (60mph + 40mph) which equals 2 hours ....???

 

[smith04]

lol actually, the one yesterday was for the 5th grader..This one was mine.... my deficiency in math has sparked an interest to relearn this stuff!

so, yes you are right...the question indicates the 2 brothers are traveling toward each other with a start time of 9am.....

T=200mi/100MHP 2 hours or 11 am....