Answer:
Height of stack = 14 feet and 3 inches
Explanation:
Height of boxes are given as following:
1) 5 feet 9 inches
2) 5 feet 12 inches
3) 2 feet 7 inches
The boxes are stacked together one on top of each other.
So height of stack = sum of heights of all the boxes
⇒

⇒

We know that [
]
So, we to convert inches to feet we divide by 12 and write the remainder in inches.
⇒

So, the quotient of
would be =2 feet and remainder =3 inches
We have,
⇒

⇒

So, height of stack = 14 feet and 3 inches