Math question i can't solve.

[Torquemonster]

Mr Lim and Mr Tan travel from town A to town B, a distance of 30 kilometres.

 

Mr lim is moving 5km/h faster than Mr Tan and Mr Lim arrives at town B an hour earlier. Find the speed at which Mr Lim is travelling.

 

can anyone help me solve this question thanks.

[Nicz]

Mr Lim (x+5) km/h, y hrs, therefore 30=(x+5)(y)

Mr Tan x km/h, y+1 hrs, therefore 30=(x)(y+1)

 

work out and you'l get y=2 or y=-3

 

sub y=2 into any equation and you'l find x=10

 

Ans: Mr Lim's speed is 15km/h

Edited April 24, 2010 by Nicz

[Jamesgetz]

bingo.

 

i hope this is not a PSLE math question...

[Vogelspinen]

Ans: Mr Lim and Mr Tan are both road hoggers.

[Torquemonster]

bingo.

 

i hope this is not a PSLE math question...

 

haha, nope, this is an 'o' level question, i am taking my 'o' level this year.

[Yorkie]

Method 2.

 

Since Mr Lim travels 5 km/hr faster and arrives 1 hr earlier, Mr Tan is traveling at speed of multiples of 5. May also use trial and error if algebra equations are not taught yet.

 

 

Speed Time to cover 30 km Remarks

 

Mr Lim 10 3hr -

Mr Tan 5 6hr -

 

Mr Lim 15 2hr ok

Mr Tan 10 3hr ok

 

 

 

 

 

[Peaceracer]

Glad i have still not lost my touch on my foundation for maths. Must be the uni engineering maths that is flooding my brain now, all the PDE, Fourier series s--t. Arrrggg, Exams tml...

[Torquemonster]

Mr Lim (x+5) km/h, y hrs, therefore 30=(x+5)(y)

Mr Tan x km/h, y+1 hrs, therefore 30=(x)(y+1)

 

work out and you'l get y=2 or y=-3

 

sub y=2 into any equation and you'l find x=10

 

Ans: Mr Lim's speed is 15km/h

 

 

thank you so much, i got the answer!

[Ara84]

Wah how come this question alot more difficult than advance calculus and linear algebra combined.

[Shull]

Glad i have still not lost my touch on my foundation for maths. Must be the uni engineering maths that is flooding my brain now, all the PDE, Fourier series s--t. Arrrggg, Exams tml...

NUS or NTU? i cleared PDE, Fourier etc 1yr back.. it was a nightmare...

[Pisces69]

thank you so much, i got the answer!

=============

 

So are you Mr.Lim or Mr.Tan then?

 

Anyway your question missed out 1 important word.

 

"Average" speed is what u r trying to find.

Edited April 24, 2010 by Pisces69

[Yattokame]

ANS: Because their speed was so low, they must be caught in a traffic jam. ERP gantry will be up along that road soon.

[Peaceracer]

NUS or NTU? i cleared PDE, Fourier etc 1yr back.. it was a nightmare...

 

NTU. Yea manz. Don really knw how to do the MSV for non homo PDEs. Nvm, laz. Jus hope that it doesnt come up. Will need to mug for my Physics le.

[Shull]

NTU. Yea manz. Don really knw how to do the MSV for non homo PDEs. Nvm, laz. Jus hope that it doesnt come up. Will need to mug for my Physics le.

 

haha...i sucked at maths too...

 

NUS engineering here btw..exams coming in 2 days time..

[Peaceracer]

haha...i sucked at maths too...

 

NUS engineering here btw..exams coming in 2 days time..

 

All the best for your papers manz!!

 

Dam it, today's paper came out PDE non homo and Complex mapping. THe only 2 things in the entire syllabus that i didnt study and they appeared.

[Kotila]

Mr Lim and Mr Tan travel from town A to town B, a distance of 30 kilometres.

 

Mr lim is moving 5km/h faster than Mr Tan and Mr Lim arrives at town B an hour earlier. Find the speed at which Mr Lim is travelling.

 

can anyone help me solve this question thanks.

 

My suggestion of a solution:

 

 

Let Mr Tan travel speed be x

and hence Mr Lim will be x+5

Time take to cover 30 km

for Mr Tan is ((30)/x)

and

for Mr Lim is ((30)/(x+5))

The time difference is 1 hr

ie. ((30)/x)-((30)/(x+5))=1

((30x+150-30x)/(x(x+5)))=1

150=x