Okay.. This is an easy task:-
I = q/t, so 2 = q/300 =>q=600 Amperes [because 5 mins= 300 secs]
R=rho * l/a
I give you a hint that you need to find new area.
Given charge is 1.6 Coulomb
Charge in 1 electron = 1.6 * 10^-19 C
No. of electrons = 1.6 / (1.6*10^-19) = 10^19 Electrons
Your question is incorrect, potential difference is measured in Volts, not Watts [you wrote Walts though]. Watt is for power.
So Charge is given as 4C, => Current for 1 sec will be 4 A.
Work done = VIT
here, time [T] = 1, so VIT = 10*4*1= 40 Joules.
=> I = 0.23 A