A box contains 400 pipe couplings. If there are four full boxes in stock and one that is 1/4 full, how many couplings are now on hand?

To determine the total number of pipe couplings on hand, we start by calculating the couplings in the full boxes. Each full box contains 400 couplings, and there are four full boxes. Therefore, the number of couplings in the full boxes is:

4 boxes × 400 couplings/box = 1,600 couplings.

Next, we need to account for the additional couplings in the box that is 1/4 full. Since a full box contains 400 couplings, a box that is 1/4 full contains:

400 couplings × 1/4 = 100 couplings.

Now, we can add the number of couplings from the full boxes to the couplings in the partially full box:

1,600 couplings + 100 couplings = 1,700 couplings.

Thus, the total number of pipe couplings now on hand is 1,700.