



 
Arul, here's a similar problem. Madame Campbell's class has 35% boys and 65% girls. M. Laurier's class has 50% boys and 50% girls. They all go to the track and field competition together and find that 45% of the combined group are boys. What percentage of the students at the competition are in Mme. Campbell's class? To solve this, let C be the number of students in Mme Campbell's class and L be the number of students in M. Laurier's class. Then the number of boys is 0.35C + 0.50L, but it is also 0.45(C+L) when they go to the track and field competition. So 0.35C + 0.50L = 0.45(C+L). First, we can solve for L:
The question asks what percentage of the whole group (C+L) is from Mme Campbell's class (C). So it is asking for the value of C/(C+L) as a percentage.
You can solve your question the same way, Arul. Cheers,  


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