Physics question help please!

Resistances of 30000 Ohms and 10000 Ohms are joined in series across a 12 V supply. What is the potential difference across the 10000 Ohm resistor?
If a voltmeter of resistance 15000 Ohms is joined across the 10000 Ohm resistor, what will it read?

I've been asked to do some marking but everyones answers/methods are different...any help?

Two ways:

1) First find the total resistance:
30,000 + 10,000 = 40,000

Then the current:
I=V/R
I=12/40000
I=0.0003 amps.

Then get the voltage:
V=I*R
V=0.0003*10000
V=3

2) Ratio of resistances:

30000/40000=.75
10000/40000=.25

12*.75=9 volts across the 40,000 ohm resistor.
12*.25=3 volts across the 10,000 ohm resistor.

Part two is trickier. I'll get back to you on that.

You're welcome, but I'm still working on part two.

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Oops, should have been:

12*.75=9 volts across the 30,000 ohm resistor.

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