A 10- $\Omega$ Resistor Is Connected in Series with a 30- $\Omega$

Multiple Choice

A 10- $\Omega$ resistor is connected in series with a 30- $\Omega$ resistor. The total resistance of the combination is

A) 7.5 $\Omega$ .
B) 15 $\Omega$ .
C) 40 $\Omega$ .
D) 300 $\Omega$ .