Thanks for that tiger.
As I thought there is a trial and error element but the clues are there to lead you in the right direction.
As you like this sort of thing, here's another:-
2 cars set off from the same point to travel the same journey
The first car has a 9 minute start.
The first car travels at 80km/h
The second car travels at 95km/h
How many km from the start will the cars draw level?
@vendasaid Thanks for that tiger.
As I thought there is a trial and error element but the clues are there to lead you in the right direction.
As you like this sort of thing, here's another:-
2 cars set off from the same point to travel the same journey
The first car has a 9 minute start.
The first car travels at 80km/h
The second car travels at 95km/h
How many km from the start will the cars draw level?
That one is a much easier question.
9 min is .15 hours
80×.15 is 12, so the first car has a 12 km lead.
The second car is traveling 15 km per hour faster than the first. Using d= rt...
12=15t and solving for t you get .8 hours.
Thanks Eladar, car-less of me!
Formula is that is car at S1 has a head start of t, it goes a distance ofS1*t
The delta speed of the two cars is (S2-S1)
So the time for the second car to catch up is
(S1 * t)/(S2 -S1)
The final distance is S2 * time so we have:
Final distance = D = S1*S2*t/(S2 - S1)
Interestingly this rearranges to
t/D = 1/S1 - 1/S2
Thanks Eladar, car-less of me!
Formula is that is car at S1 has a head start of t, it goes a distance ofS1*t
The delta speed of the two cars is (S2-S1)
So the time for the second car to catch up is
(S1 * t)/(S2 -S1)
The final distance is S2 * time so we have:
Final distance = D = S1*S2*t/(S2 - S1)
Interestingly this rearranges to
t/D = 1/S1 - 1/S2
Yeah thought about it. You just made a formula of the steps I went through. In the US we like to use basic formulas then build answers instead of simplified formulas for specific cases.
@iamatiger You're obviously a very qualified mathematician.
What level have you achieved academically?
I detested mathematics at school but later in life my interest was sparked when I saw a problem in a newspaper about someone trying to fill up a bath with the plug out!!(why would yo do that?)
I couldn't work it out and it annoyed me so I got a book out of the library and it all started from there.
People then started buying me mathematical puzzle books for birthdays and xmas which is where most of the ones I put on here come from