orginal of this task in [flag=pl language]
Pociag zostal zatrzymany na stacji dodatkowo o t minut. Chcac nadrobic opoznienie zwiekszono predkosc pociagu o a kilometrów na godzine. Po przejechaniu b kilometrów opoznienie zlikwidowano. Jaka byla planowana predkosc pociagu?
The train tried to skip a few stations, so he switched rails and got in a huge accident hitting another train heading from the opposite direction. 12 people died, 18 were severely injured, the remaining 42 people got rescued and transported to safety, gg.
I haven't any tips or solution coz it's one of competition task and I need to solve it if I want to qualify in final :/ Can you tell me now how did you solve it?
Now I'm 90% sure I will study in Cracow but I'm ambitious (sometimes even too ambitious) and I try to take part in many competitions. This is last stage before final in Warsaw, actually solved 7/10 tasks and I won't give up now :) To the final qualify 150 participants and I have time until the end of the month to send all solutions.
ye I understand you but there is only a, b and t and i have to use only this three letters in solution
e: oh wait im idiot
e2: it seems that you're right
after ordering I've got
v^2t-atv+ab=0 (smth like ax^2+bx+c=0)
v= sqrt(at(at-4b))-at or v=-sqrt(at(at-4b))-at
everythings seems to be ok but when i substitute letters by any numbers which solve your equation i've got v less than 0 in both cases
anyway thanks a lot :)
rofl now I know where I did a mistake :D
in (at(at-4b)) should be "+" instead of "-" and now everything is ok
thanks! If I meet you in real I'll buy you beer :)
think of a traingle
(v+a)*[(b/v)-t]=b
?
e: oh wait im idiot
e2: it seems that you're right
after ordering I've got
v^2t-atv+ab=0 (smth like ax^2+bx+c=0)
v= sqrt(at(at-4b))-at or v=-sqrt(at(at-4b))-at
everythings seems to be ok but when i substitute letters by any numbers which solve your equation i've got v less than 0 in both cases
anyway thanks a lot :)
i guess solution 2 is the one you are looking for since its gonna be "+"
in (at(at-4b)) should be "+" instead of "-" and now everything is ok
thanks! If I meet you in real I'll buy you beer :)
edit: planned speed 70km/h