Дано: 
$$ Q_2=Q_1 q\cdot m_2 = c\cdot m_1\cdot (t-t_0) m_1= \frac{q\cdot m_2}{c\cdot (t-t_0)} = \frac{30\cdot 10^6\cdot 2,1}{4200\cdot (85-25)}=250 (\_K_\Gamma) $$