Answer:
B) 13
Step-by-step explanation:
Average age means to calculate mean:
Mean = (Sum of all numbers)/(Number of numbers)
Mean = (14 + 14.5 + 12 + 11.5 + 15 + 13 + 10.5 + 13.5)/8
Mean = (104)/8
Mean = 13
Let

be the length of the rectangle and

be the width. In the problem it is given that

. It is also given that the area

. Substituting in the length in terms of width, we have

. Using the zero product property,

. Solving these we get the width

. However, it doesn't make sense for the width to be negative, so the width must be

. From that we can tell the length

.