Data Sufficiency

On this Christmas, Merry is planning to throw a great meat party for all of her relatives and friends. Bearing minimum budget to mind, she decides to order few large 5 Kg turkeys, few medium 3.5 Kg birds, and few modest 1.5 kg turkey crowns. Merry has 20 more friends than her relatives. Assuming each of the turkey, bird, and turkey crown serves for a given number of guests and each guest consumes only one kind of meat, how many guests does Merry plan to invite on her great meat party this Christmas?

(1) Merry knows that a large 5 kg turkey will serve 10 guests; a medium 3.5 kg bird will serve 6 guests, while a modest 1.5 kg turkey crown will serve 4 guests.

(2) Merry plans to order 3 large 5 Kg turkeys, 1 medium 3.5 Kg bird, and 3 modest 1.5 kg turkey crowns only for her friends' servings.


Made Up!

[spoiler]Is Christmas over, Merry? Reader's ignorance encourages me do changes in the question. My answer is C now.[/spoiler]

Let # Merry's relatives be X
Therefore, # Merry's Friend =X+20
Each person consumes only one kind of meat, also let us assume that each guest eats only one portion of meal,
Therefore, # of servings available = # of guests
or # of servings / # of guest = 1

Statement#1 INSUFFICIENT
Statement#2 INSUFFICIENT

Together Statement 1&2

3(10)+1(6)+3(4) = X+X+20
48 = 2X+20
X = 14

Therefore, # of Guest = 14+14+20 = 48

Instead of solving for X, we could have got number of guest right away just by calculating total number of servings.

Gaj81 wrote:Let # Merry's relatives be X
Therefore, # Merry's Friend =X+20
Each person consumes only one kind of meat, also let us assume that each guest eats only one portion of meal,
Therefore, # of servings available = # of guests
or # of servings / # of guest = 1

Statement#1 INSUFFICIENT
Statement#2 INSUFFICIENT

Together Statement 1&2

3(10)+1(6)+3(4) = X+X+20
48 = 2X+20
X = 14

Therefore, # of Guest = 14+14+20 = 48

Instead of solving for X, we could have got number of guest right away just by calculating total number of servings.

DS Answer-wise you are correct, but had it been a PS problem, you'd have lost it. If you read the statements carefully, you'd notice that the left-hand-side of your this work "3(10)+1(6)+3(4) = X+X+20" represents the number of servings for her friends only, while the right-hand-side represents the number of all her relatives and friends. This imbalance leads to a wrong answer in the end.