l=1200m=1,2 km
t1=20min=4/12 h
t2=5min=1/12 h
v1=?
v2=?
s=v*t
dla tego samego kierunku: v1*t1-l=v2*t1
dla przeciwnego: v1*t2=l-v2*t2 -> v1=(l-v2*t2)/t2
((l-v2*t2)/t2)*t1-l=v2*t1 /*t2
(l-v2*t2)*t1-l*t2=v2*t1*t2
l*t1-v2*t1*t2-l*t2=v2*t1*t2
-v2*t1*t2-v2*t1*t2=-l*t1+l*t2 /*(-1)
v2(t1*t2+t1*t2)=l*(t1-t2)
2*v2*t1*t2=l*(t1-t2)
v2=l*(t1-t2)/(2*t1*t2)
v2=1,2*(4/12-1/12)/(2*4/12*1/12)
v2=1,2*(3/12)/(8/12)
v2=0,575 km/h
v1=(l-v2*t2)/t2
v1=(1,2-23/40*1/12)/(1/12)
V1=(553/480)/1/12
v1=13,825 km/h
