Chaoyun L. answered • 10/26/15
Tutor
1
(1)
Master of Math with concentration in Statistics
Let the number of students be x. Since there were 300 people at the game, the number of adults can be expressed in 300 -x. The relationship between students and adults is that there are 60 more students than adults. So x-60 = 300 -x.
2x = 360
x=180.
Then the # of students is 180; the #of adults is 120. They add up to 300 and satisfy the relationship that there were 60 more students than adults.
Heng X.
tutor
B,
Let say that the number of students and adults are the same, total 300 of them, so each group will have 150.
We know that students are more than adults. Let's say that 1 adult turns to a student. Now we have 151 students and 149 adults. Notice the difference between adults and students is 2 = 151 - 149. Saying that for each student that exceeds 150, we have the difference of 2 between adults and students.
Another way of looking at it is that for each additional student, the number of students increase by one, at the same time, the number of adults decreases by one, that is how you get a difference of 2.
Now we know that the difference between those two groups is 60. Students much exceed 150 by half of 60 (30), because adults will have to reduce by 30 at the same time.
Students : 150 + 30 = 180.
Hope it makes sense.
The general situation here is that when the total is fixed, increasing one group will lead to decreasing of the other. Say, you and your 8-year-old are splitting a dollar, any penny moved from one person to the other will increase the gap between you by 2 pennies.
Best,
Heng
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10/30/15
B. D.
Thank you!! Bless you so much...you are a Genius.
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11/04/15
B. D.
Going over this problem, this weekend.
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11/04/15
B. D.
10/26/15