Resistor calculations

[dsrviola]

I know there's a formula for figuring out the value of resistors in parallel; I've seen it before. However, I don't remember it, and my algebra is so rusty that I wouldn't be able to figure it out anyway. Here's the puzzle:

I need to come up with a value of 5.2-5.25 (maybe 5.3) ohms using the following values: 0.1, 0.5, 1.0, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.7, 3, 3.3, 3.5, 3.7, 4, 4.3, 4.5, 4.7, 5, 5.5, 6, 6.5, 7, 7.5, 8, 9, 10, 11, 12.5, 15, 20, 25, 30, 47, 82, 100 and they have to be in parallel. Nothing in series. Preferably with just 2 resistors. Can anyone help me with this, or point me in the right direction?

Thanks!

[real]

Hi,

Formula for the equivalent resistance of 2 resistors in parallel is R1*R2/(R1+R2).

To get the value you require, use 10 and 11 ohms, the formula gives 110/21=5.24ohm.

For more than 2 resistors in parallel, the equivalent resistance (Rt) is given by: 1/Rt = 1/R1 + 1/R2 + 1/R3 +...

Regards,

Chris.

[pinkmouse]

Homework from school?

R= (R1*R2)/(R1+R2)

[dsrviola]

Thanks guys!