2015 · Q6
The average of m numbers is n^4 and the average of n number is m^4.The average of (m + n) numbers is
Elementary MathematicsNumber System
- Amn
- Bm²+n²
- Cmn(m²+n²)
- Dmn(m²+n²-mn)
Explanation
Sum of the first set = m*n^4 and of the second = n*m^4. The combined average is (m*n^4 + n*m^4)/(m + n) = mn(n^3 + m^3)/(m + n) = mn(m^2 + n^2 - mn). Hence option (d).