Question 11
Real numbers $a,b,c$ are stated to satisfy
$\frac{ab}{a+b}=4,\qquad\frac{bc}{b+c}=6,\qquad\frac{ac}{a+c}=12.$
What is the value of $\frac{abc}{ab+bc+ac}$?
Interpretation: Check that the original real-number conditions are consistent. If no real triple exists, use E (“None of the above”); do not assign a value merely from formal manipulation.
$\frac{ab}{a+b}=4,\qquad\frac{bc}{b+c}=6,\qquad\frac{ac}{a+c}=12.$
What is the value of $\frac{abc}{ab+bc+ac}$?
Interpretation: Check that the original real-number conditions are consistent. If no real triple exists, use E (“None of the above”); do not assign a value merely from formal manipulation.