The average age of M boys is â€˜bâ€™ years and of â€˜nâ€™ girls â€˜câ€™ years. The average age of all together is?
Choose the correct choice:
A) (mb + nc)/ (m + m) years	B) (mb + nn)/ (m + n) years	C) (mb + nc)/ (m + n) years	D) (nb + nc)/ (m + n) years	E) (mn + nc)/ (m + n) years
Explanation:   (mb + nc) / (m+ n)   Answer:(mb + nc)/ (m + n) years
<result>C</result>
The average age of M boys is â€˜bâ€™ years and of â€˜nâ€™ girls â€˜câ€™ years. The average age of all together is?