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at-a-blind-taste-competition-a-contestant-is-offered-3-cups-of-each-of-86830.html#p651981 Can someone help me identify what am I missing and whats wrong with this approach.

In your first case (1112), you chose a tea which would have 3 cups chosen (3C1). Then, you also had to choose a tea that would have 1 cup chosen (2C1). This is correct. This term (3c1 x 3c3 x 2c1 x 3c1 = 18) is correct imo. Your second case (1122) is where I think the error is. In reality, both the teas chosen have 2 cups chosen each. In other words, you should actually do 3C2 (in how many ways can I choose 2 teas out of 3 for the purposes of taking 2 cups each from the tea). So, actually 3c2 (2 choose the 2 teas) x 3c2 (for cups - 1 of the 2 teas chosen) x 3c2 (for cups - the other tea chosen) = 27. This gives a total of 45. 45/9c4 = 5/14. In essence, i believe that a double count is happening in your 2nd case (1122) because of the 2C1. I found it easier to use the complement method here. 1 - (no of ways of ensuring at least 1 tea is tasted). Edit: I meant 1 - P(all 3 teas are tasted at least once) Judgement call in my case. But if you think about it, the first question asks us to find max value of "B alone". This does suggest that even if I work with (A+B+C - (II ) - 2(III)), I would eventually need to arrive at B alone. Hence, why not use - a+b+c+d+e+f+g+n(none) = total.

No, Volume that is empty - 1- 3/5 = 2/5 X x 3/5 = 8 hours X = 40/3 time to fill remaining 2/5 pool 40/3 x 2/5 = 16/3 hours = 320 min = 5 hours 20 min Hence (B) is the answer.

Your calculation -> 8 x .4/.6 is correct. This gives 32/6 = 5.333... This is not 5h 30 min. This is 5h and 0.3333 i.e. 1/3 of an hour. i.e. 5h 20 min. 5h 30 min is 5.5, not 5.3333.

Why is this not the answer/the way, What’s wrong in this?!

Last question of Jamboree GMAT book. I’m confused here.

When two people work together, the number of days taken to do the work would decrease. But by adding 15+18 you are increasing the time to do a work. So 12 days for x. But for y and z combined, find one days work by 1/15 + 1/18 or 33/18*15 or 11/90. or days = 90/11 Thus ratio = 12 : 90/11 = 132:90 = 22:15 or 22/15

Why don’t we divide 1 by 12 in the numerator as well. Like 1/12/(1/15+1/18)

you can do that but that will give you ratio of one day work. It will come out to be 15/22. take its reciprocal to get ratio of number of days.

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