Is this a trick question? Trying to help daughter with pre-algebra homework and this question seems out of place.

I'm thinking that bundle means a minium of 2 cards and that the answer is 10.David is packing bundles of 3-inch by 5-inch cards, face up, into a square box. He

places the cards side-by-side so that there is no wasted space. Find the smallest possible

measure for the edge of the box.