ANSWER: x=12
EXPLANATION:
9+x/6=11
(54+x)/6=11 (finding common denominator)
x/6=11-54/6 (rearranging terms)
x/6=(66-54)/6 (finding common denominator so 6 gets cancelled from both the sides)
x=12
Circular based pyramid I believe
There are 4 doughnuts in 1/3 of a dozen
The Second Choice I think