Answer:
please write in english language so that we can help you
Clarify what you mean by ratios?
i do not know.....................................
The total capacitance is <em>C</em> such that
1/<em>C</em> = 1/(5.0 µF) + 1/(14 µF) + 1/(21 µF)
Solve for <em>C</em> :
<em>C</em> = 1 / (1/(5.0 µF) + 1/(14 µF) + 1/(21 µF)) ≈ 3.1 µF