MathIzzzFun:

CJ-2011:

Any kind soul can explain the rationale behind the solution for question PSP102, pg 368 of \"Problem Solving Processes in Maths (New Syllabus)\" by Fabian Ng ?


The problem is listed below :-

At 0800, Noel left town A for town B while Jane left town B for town A. At 1600 their cars passed each other. 5 hour later Jane reached town A but Noel was 240km away from town B,
a) How long after they start before they passed each other
b)Find the distance between the two towns

Solution :
a) 1600 - 0800 = 0800
Each driver had driven for 8 hr when they passed each other.

b) 240 / (8-5) = 80
The total speed of the two drivers was 80 km/h

80 x 8 = 640
The two towns was 640 km apart
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I cannot comprehend and explain the part (b) on total speed. Is this some form of relative speed ? Is the concept of total speed taught in school ?

Thanks

hi

hope this helps

http://i52.tinypic.com/16i87ic.jpg\">

cheers.

Thanks a great deal. Fabian should re-write his solution, the way you presented yours. Thks again !

Any kind soul can explain the rationale behind the solution for question PSP102, pg 368 of "Problem Solving Processes in Maths (New Syllabus)" by Fabian Ng ?


The problem is listed below :-

At 0800, Noel left town A for town B while Jane left town B for town A. At 1600 their cars passed each other. 5 hour later Jane reached town A but Noel was 240km away from town B,
a) How long after they start before they passed each other
b)Find the distance between the two towns

Solution :
a) 1600 - 0800 = 0800
Each driver had driven for 8 hr when they passed each other.

b) 240 / (8-5) = 80
The total speed of the two drivers was 80 km/h

80 x 8 = 640
The two towns was 640 km apart
----------------------------------------------------------------
I cannot comprehend and explain the part (b) on total speed. Is this some form of relative speed ? Is the concept of total speed taught in school ?

Thanks