Question

Four resistors when connected in series give an equivalent

resistance if 75.0 Ω. Three of the resistors have values 18.0 Ω, 6.0 Ω, and

24.0 Ω, respectively. What is the resistance of the fourth resistor?

Answer 1

Answer

So the fourth resistance is

$R_4=R-R_1-R_2-R_3\\=75-(18+6+24) \\=27\Omega$