Alan, Beth, Cathy, and David went to the cafeteria to have lunch.
Aside from a main dish, each of them ordered two side dishes. These side dishes
that have ordered by them were mashed potatoes, baked beans, garden salad, and
rice.
To solve this puzzle, create a table below with Y
representing side dishes chosen, and X representing side dishes not chosen.
Since Alan had mashed potatoes, Beth had baked beans, Cathy had
garden salad, and David had rice, we have

mashed potatoes 
baked beans 
garden salad 
rice 
Alan 
Y 



Beth 

Y 


Cathy 


Y 

David 



Y 
Since Alan and Beth had no side dish in common, while Cathy and
David had no side dish in common, we have

mashed potatoes 
baked beans 
garden salad 
rice 
Alan 
Y 
X 


Beth 
X 
Y 


Cathy 


Y 
X 
David 


X 
Y 
Dave did not ordered baked beans, therefore he also ordered mashed
potatoes.

mashed potatoes 
baked beans 
garden salad 
rice 
Alan 
Y 
X 


Beth 
X 
Y 


Cathy 


Y 
X 
David 

X 
X 
Y 
Therefore David also ordered mashed potatoes. Since Cathy and
David had no side dish in common, Cathy ordered bake beans but did not
order mashed potatoes

mashed potatoes 
baked beans 
garden salad 
rice 
Alan 
Y 
X 


Beth 
X 
Y 


Cathy 
X 
Y 
Y 
X 
David 
Y 
X 
X 
Y 
Beth and Cathy had one side dish in common. Therefore Beth
must have ordered rice. Since Alan and Beth had no side dish in common,
Alan ordered rice.

mashed potatoes 
baked beans 
garden salad 
rice 
Alan 
Y 
X 
Y 
X 
Beth 
X 
Y 
X 
Y 
Cathy 
X 
Y 
Y 
X 
David 
Y 
X 
X 
Y 
Therefore,
Alan had
mashed potatoes and garden salad,
Beth had
baked beans and rice,
Cathy had
baked beans and garden salad,
David had
mashed potatoes and rice.
