I'm having a bit of trouble with the explination that the OG gives. Any help is greatly appreciated.
Of the 84 parents who attended a meeting at a school, 35 volunteered to supervise children during the school picnic and 11 volunteered both to supervise children during the picnic and to bring refreshments to the picnic. If the number of parents who volunteered to bring refreshments was 1.5 times the number of parents who neither volunteered to supervise children during the picnic nor volunteered to bring refreshments, how many of the parents volunteered to bring refreshments?
A) 25
B) 36
C) 38
D) 42
E) 45
OA is B
I'm approaching the problem by setting up two equations: X=1.5Y, where X represents the number of parents who bring refreshments and Y represents the number of parents who don't volunteer to do anything.
The second equation I set up, which is wrong according to the book, is: 24+11+X+Y=84. I know the standard formula of Group1 + Group2 + Neither - Both = Total. However, Since we can isolate the amount for both, we should include it when we calculate the total.
The second equation that the OG gives is Y+24+X=84. I can't seem to understand why the 11 parents who are doing both are not included. The 24 in this equation just represents those parents who are only supervising, and, presumably, the X represents only those bringing refreshments. Thus, the 11 parents who do both, in my mind, are not counted.
Any insight into the logic of this problem will be greatly appreciated.
I apologize for this ridiculously long post. Thanks guys and good luck with the studying.
Of the 84 parents who attended a meeting at a school, 35 volunteered to supervise children during the school picnic and 11 volunteered both to supervise children during the picnic and to bring refreshments to the picnic. If the number of parents who volunteered to bring refreshments was 1.5 times the number of parents who neither volunteered to supervise children during the picnic nor volunteered to bring refreshments, how many of the parents volunteered to bring refreshments?
A) 25
B) 36
C) 38
D) 42
E) 45
OA is B
I'm approaching the problem by setting up two equations: X=1.5Y, where X represents the number of parents who bring refreshments and Y represents the number of parents who don't volunteer to do anything.
The second equation I set up, which is wrong according to the book, is: 24+11+X+Y=84. I know the standard formula of Group1 + Group2 + Neither - Both = Total. However, Since we can isolate the amount for both, we should include it when we calculate the total.
The second equation that the OG gives is Y+24+X=84. I can't seem to understand why the 11 parents who are doing both are not included. The 24 in this equation just represents those parents who are only supervising, and, presumably, the X represents only those bringing refreshments. Thus, the 11 parents who do both, in my mind, are not counted.
Any insight into the logic of this problem will be greatly appreciated.
I apologize for this ridiculously long post. Thanks guys and good luck with the studying.
