Understanding Voltage Drop with Resistances.

Hi, I just started a course (Basic Electricity) and I was wondering if you could help! DC = 60 V R1 = 6.8 k ohms (in series) R2 = 12 k ohms R3 = 6.2 k ohms R4 = 12k ohms (in parallel) Note: R1 in series and the rest in parallel (R2, R3, R4). 1/R t = 6.2/74.4 + 12/74.4 + 6.2/74.4 = 24.4/74.4 R t = 1 / (24.4/74.4) = 1/0.327957 = 3.049 Ohms