LED value question

i bought 3 LED in a series connection, now my question is how do I find out the value of each LED as far as voltage and forward current using the resistor that's used on all three.....what 'm planning to do is use each LED separately so that's why I need their actual value so I can get the right resistor for a 12v power supply........BTW it's the blue type of LED if this helps........i tried lighting it up using a 9v battery and switched between 3.4v and 4.6v values and 12milliamps and 10milliamps to get the right resistor but it didn't work...

thanks in advacne..........

If its still connected in series with the resistor. Measure the voltage drop across the resistor when you supply it with the voltage this connection is rated for ex 12v.

To find the current through the LEDs divide the voltage drop of the resistor by the resistor value.

To find the voltage drop of the each LED minus the supply voltage by the drop across the resistor and then divide this by 3. This will give you the voltage drop of each LED.

Then you can use those values to find the new resistor value. Hope this helps.