?

Total resistance: 18 Ω

Total current: 0.5 A

VR1: 2.5 V

VR2: 1.5 V

VR3: 5 V

Explanation:

Two formulas/laws you have to know:

1) Resistors in series: Rtotal = R1 + R2 + ... (sum the individual resistors)

2) V=I·R a.k.a.  I=V/R a.k.a. R=V/I (same formula in 3 shapes)

So, total resistance is sum off all three: 5+3+10 = 18Ω

Total current: I=V/R, V=9, R=18, so I = 9/18 = 0.5A

Voltage across resistor: V=I·R, I=0.5A (for all three), R=5 (for R1), so V = 0.5·5 = 2.5V. Same for the other three.

As a double check, the sum of the voltages must equal the battery voltage again, no volts ever get lost: 2.5+1.5+5 = 9V (check!!)

what? ? i don't get it