The current in a conductor is expressed as I = 3 t ^ 2 + 4 t ^ 3 ,...

For variable current, integrate to get the total charge flown in a given interval.$q = {∫}_{1}^{2}idt = {∫}_{1}^{2}\left(3{t}^{2} + 4{t}^{3}\right)dt$

${⇒ q = \left({t}^{3} + {t}^{4}\right)}_{1}^{2}$

$⇒ q = 22C$