Adult math class

Number Theory Level 2

In an adult evening math class, the average age of the class of men and woman is 36. The average age of men is 45, and the average age of the woman is 30. What is the ratio of the woman to men in the group?

2:3 3:1 3:2 4:2 1:1

Vasudev Rajeeve by Vasudev Rajeeve , 16, Canada

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1 solution

Vasudev Rajeeve
Mar 25, 2018

36(x+y) = 45x + 30y

36x + 36y = 45x + 30y

36y - 30y = 45x - 36x

6y = 9x

y = 9/6 x

y = 3/2 x

So the ratio of woman to men is 3:2

0 Helpful 0 Interesting 0 Brilliant 0 Confused

In general, the ratio of men to women is the absolute value of the men's average - the average of all the people : the absolute value of the women's average - the average of all the people. In this case it is 45-36:36-30 = 9:6 = 3:2

Daniel Xian - 2 years, 4 months ago

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