Okay, so looking at the numbers.
1 foot =12 inches
2*12= 24+5= 29 inches
Second box
3*12= 36+3=39
Adding both of those numbers, 29 and 39 you get 68 inches.
So, if you combine the boxes, you get 5 feet and 8 inches.
The answer in inches is 68, and the answer in feet and inches is 5 feet, 8 inches.
Hope this helps!