Stacey Koprince wrote:Please spell out exactly what you are doing, step by step, so that we can examine it and help you to figure out what's going on. Actually show us the math!
Here is a similar question. The only difference is that this problem has values instead of percentages. I tried to solve your problem the same way, but couldn't.
In a certain sports club, members are placed in at least one of the three groups. There are 70 members in the soccor group. 80 members are in the hockey group, and 90 members are in the football group. There are 7 members in both soccor and and hockey groups. 8 members in both hockey and football groups, and 9 members in both soccer and football groups. There are 2 members that are in all three groups. How many members are there in total in the sports club ?
First: # of members who are in all three groups = 2
Second:
# of members who are ONLY in Soccer and Hockey groups = 7-2 = 5
# of members who are only in Hockey and football is groups = 8-2 = 6
# of members who are only in soccer and football group = 9-2 = 7
Third:
# of members who are only in soccer group = 70-2-5-7 = 56
# of members who are only in Hockey group = 80-2-5-6 = 67
# of members who are only in football group = 90-2-6-7 = 75
Finally, Total number of members in the club + (56+67+75) + (5+6+7) + (2) = 218
The MGMAT question seems identical, but something is wrong !
