Equivalent resistance if the values of the two resistances

[XodoX]

Two resistors are in series. Find the equivalent resistance if the values of the two
resistances are as follows.
a) 10 [Ω] and 20 [Ω].
b) 100 [Ω] and 1 [MΩ] (M stands for “Mega” or million).
c) 3.0 [kΩ] and 6.7 [kΩ] (k stands for “kilo” or thousand).
d) 400 [Ω] and 1 [Ω].

Repeat the above problem, assuming that the resistors are in parallel.



Can anybody hel me with this, please? I have no idea how to start/do this.

Thank you!

 

[Defennder]

To start you off, what do you know about how to find equivalent resistance of resistors in series and parallel?

 

[XodoX]

parallel has the same voltage and the current in series stays the same?

 

[M11]

Series resistors:

R_equivalent=R₁+R₂+R₃+...+R_n

______________________________________________________

Parallel resistors:

( 1/ R_equivalent) = ( 1 / R₁) + ( 1/ R₂) +...+ ( 1/ R_n)

OR you can use the following equation if you have two parallel resistors:

R_equivalent=$$\frac{R1 \times R2}{R1 + R2}$$

 

[XodoX]

So I just add them? a) would be 30 then.
Thank you, that works:)