SIMPLE e&m question: finding equivalent capacitance

[offbeatjumi]

I am missing something very simple... in my book, it gives, for capacitors in series, that:

1/C(eq) = 1/C(1) + 1/C(2)
using numbers, it says...

1/C(eq) = 1/6.0 uF + 1/3.0 uF ... C(eq) = 2.0 uF

I cannot figure out how they got C(eq) = 2.0 uF

Thanks

 

[mdxod]

1/Ceq = 1/6 + 1/3 --> 1/6 + 2/6 = 3/6

3/6 = 1/2 = 1/ Ceq...

to find Ceq flip --> Ceq = 2uF