Multiple choice general knowledge math & puzzles A natural number is halved when reduced by thirteen. Find that number! 13 26 28 39 Reveal answer Fill a bubble to check yourself B Correct answer Explanation Let the number be x. The problem states that when 13 is subtracted from the number, the result is half the original number: x - 13 = x/2. Multiply both sides by 2: 2x - 26 = x. Subtract x from both sides: x = 26.