5 + 6 = 11 ведер
cm1(t-t1)=cm2(t2-t)
m1*t-m1*t1=m2*t2-m2*t
(m1+m2)*t = m1*t1+m2*t2
10*5 + 90*6 = t*11
t = (50+540)/11 ≈ 53,6°