.

https://isaacphysics.org/questions/maths_ch7_3_q9?stage=a_level

cannot do part f, please help. i have tried m(t) = (m_0 - qt) (1 + p/100)^t, and m(t) = (m_0 - qt)e^((pt)/100) and don’t have much of a clue of what i’m doing. i don’t know if you have to solve the differential equation dm/dt = pm/100 - q, but i can’t solve that either because i want to integrate with respect to t but m is also there, so i can only ever get t(m) and not m(t).

any help would be much appreciated, thank you