Answer :
Answer 1 : electrons was transfered from the rod to the metal inducing a positive charge on the metal surface close to the rod.
Explanation: in static electricity, electron always flows to or away from a particle. In this case, the charge rod contains loose excited electrons. On contact with the metal surface, most of the free electrons move from the rod to the metal to even up the charge on the rod. This leaves a positive induced charge on the metal surface in contact with the rod.
Answer 2: approximately 3*10^10 electrons were transfered.
Explanation: the initial charge on the rod was -15nC = -15*10^-9C
Final charge = -10nC = -10*10^-9C
Charges lost = -10nC - (-15nC) = 5nC of charges.
Charge on an electron particle = -1.6*10^-19 the minus indicates that the electron carries a negative charge.
Total number of particles transfered becomes;
n = (5*10^-9)/(1.6*10^-19) = 3.125 *10^10 electron
Approximately 3*10^10 electrons.