Answer:
4.18 μC
Explanation:
given,
charge place at the center of conducting spherical shell = -3.07 μC
total charge place in the shell itself = +7.25 μC
to calculate charge on the outer surface = ?
total charge on the outer surface = +7.25 μC - 3.07 μC
= 4.18 μC
hence, the charge on the outer surface of the shell is 4.18 μC