What is the voltage across each resistor of 90V battery R is the lowest-value resistor, and all
others are multiples of that value as indicated.
R = 10Ω
R2 = 20Ω
R3 = 40Ω
R4 = 80Ω
The voltage across each resistor is:
R = 10Ω: 9V
R2 = 20Ω: 18V
R3 = 40Ω: 36V
R4 = 80Ω: 72V