Lets say there are total 100 Guests. We are told 75 ordered Deseret, and we have to calculate % of people who ordered coffee
So what we need is no of people who ordered coffee which is no of people who ordered only coffee and and number of people who ordered both coffee and desert.
Stmt 1: Tells us no of people who ordered both = 45, So if 45 ordered both then only 30 ordered only desert. but we have no information on no of people who ordered only coffee and no of people who ordered none.
Stmt 2: 90 % of those who ordered coffee also ordered desert. Since we don't have the values of those who ordered coffee or those who ordered coffee and desert we cant calculate any thing from this information.
Now we already know from second statement if we have information about no of people ordering both we can calculate no of people who ordered coffee.
So combining Stmt 1 and Stmt 2, We have
90% of x= 45, so x =50, this is number of people who ordered coffee. So we can calculate the required % which is about 50 %
So Only Desert 30, Desert & Coffee 45, Only Coffee 5, 20 none , which gives total 100.
Probus
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Probus
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