Question

If A + B + C = 43 and A + B - C = 17 then the average of A and B is

Answer 1

A+B+C=43     and     A+B-C=17

\(\Rightarrow A+B=\frac{43+17}{2}\)

\(\Rightarrow A+B=30\)

\(\Rightarrow\frac{A+B}{2}=\frac{30}{2}=15\)

=> The average of A and B is 15