V on capacitor = 12V - 2V = 10V
now,charging formula for a capacitor is: Vs=Vi(1-[e to the power of t/RC])
where Vs is the supply voltage
Vi is the voltage on capacitor
t is the time
R is the resistor
and C is the capacitance
therefor your formula will becoma 12=10(1- [e to the power...