Based on the given, this is probably a gravitational potential energy problem (PEgrav). The formula for PEgrav is:
PEgrav = mgh
Where:
m = mass (kg)
g = acceleration due to gravity
h = height (m)
With this formula you can derive the formula for your unknown, which is mass. First put in what you know and then solve for what you do not know.

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Do operations that you can with what is given first.

Transpose the 100 to the other side of the equation. Do not forget that when you transpose, you do the opposite operation.
m = 0.30kg
Answer:
300kgm/s
Explanation:
Given parameters:
Mass of TV = 30kg
Height of building = 5m
Maximum speed = 10m/s
Unknown:
Momentum before it hits the ground = ?
Solution:
Momentum is the quantity of motion a body possess or contains. It is expressed as;
Momentum = mass x velocity
Insert the parameters and solve;
Momentum = 30 x 10
Momentum = 300kgm/s
Answer:
2.00 A
Explanation:
Total resistance = 10 + 20 + 30 = 60 ohms
Potential difference (V) = 120volts
Current (I) =?
from Ohms law V = IR
==> I = V/R = 120/60 = 2 A
Note: for resistors in series equal amount of electric current flows through the circuit
The least value varies depends on ammeter range. In the given question, ammeter range is not mentioned. So, the least value of an ammeter is 0.1 or 0.5 (depends on ammeter range).
<u>Explanation:</u>
The least value of an ammeter is the measure of the smallest number which can be observed in ammeter. So the least value will be varying depending upon its range. If we consider the range of ammeter is 30 A and the scale readings are 10 numbers, then the least value will be 30/10 = 3 A per scale.
So the least value is determined as 
So among the given options 0.1 is most suitable for an ammeter with range of 3 A with 30 divisions.