Be cool!

We can derive the formula for resistors in series.

Suppose we have an electric circuit with two resistors connected in series, we will observe that the total voltage $V=V_1+V_2$

But, we find that the current doesn't differ in this case, therefore by Ohm's law(taking the both the resistors as one),

$V=IR$

Now, by applying Ohm's law to individual resistors,

$V_1=IR_1$ . . . .1

$V_2=IR_2$ . . . .2

Adding 1 and 2, $(V_1+V_2)=IR_1+IR_2$

But $V_1+V_2=IR$

therefore, $(IR)=IR_1+IR_2$

Or, $R=R_1+R_2$

Applying the values, $R = 5+5=10 ohm$

For resistors connected in series the formula is R=R+R2+R3=5+5=10 ohm.

It's easy since they are connected in series,

$Rtot = R_{1} + R_{2}$

then

$Rtot=5 \Omega + 5 \Omega$

$Rtot=10 \Omega$

in series combination of resister we have R=R1+R2 SO R=5+5=10ohm

Its quite easy, it is a good question

Total RESISTANCE in series = R1 + R2 + ..... + Rn

So, Total R = 5 + 5 = 10ohms