To form a triangle, the sum of two side lengths must be greater than the length of the third side. Taking the two shortest lengths, 2 and 3 inches, their sum is 5 inches which is not greater than 5 inches.

Hence, the combination that will not work is: 2 inches, 3 inches, 5 inches

Hence, the combination that will not work is: 2 inches, 3 inches, 5 inches