Detailed Instructions: You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
Problem:Question: The average age of M boys is 'b' years and of 'n' girls 'c' years. The average age of all together is?

Option A: (mb + nc

Option B: (mb + bc

Option C: (mb + nc

Option D: (nb + nc

Option E: (mb + nb
Solution:
Option C