The length of the table when both leaves are folded up is 7 ft.
The length of the table when one of the leaves are folded up is 5.5 ft.
So if you do:
7 - 5.5 = 1.5
1.5 ft is the length of one of the leaves (remember the two drop leaves are the same size)
How long is the table when no leaves are folded up?
One leaf is 1.5 ft.
Since there are two leaves, the total length of the leaves is 3 ft.
7 - 3 = 4
[7 is the length of the table when both of the leaves are folded up, 3 is the length of both of the leaves]
4 ft is the length of the table when no leaves are folded up
