" <em>Energy is never created or destroyed.</em> "
All the rest is commentary.
Question :
If a body acquires a charge of -0.02 C, has it gained or lost electrons? Many?
Solution :
We know, charge gained is shown by negative sign.
Since, charged acquired is given as -0.02 C .
Therefore, it is body has gained electrons.
Now, number of electrons is given by :

Hence, this is the required solution.
A bowler who always left the same 3 pins standing could be considered a C. Precise bowler as from bowling countless number of times he has observed the same amount of pins knocked down each time.
To calculate the gravitational force acting on an object given the mass and the acceleration due to gravity, use the following formula.
Fg = m • g
Fg = 1.3 kg • 9.8 m/s^2
Fg = 12.74 N or about 12.7 N.
The solution is C. 12.7 N.