ok, are you wanting to know how to find out the voltage of each resister, in parallel?
or what the total resistance is in parallel?
for total resistance in parallel--
take the rating for each resister, divide it by 1 (to get reciprocal), then add them together, then divide it by 1 again, to get a whole number.
5, 10, 10 (in parallel) = 2.5Ohms.
(better explained here)♠
a good description of the Voltage drop on resistors is also there.