Multiple choice general knowledge math & puzzles Divide 30 by 1/2 and add 10. What is the answer? 30 60 0 70 Reveal answer Fill a bubble to check yourself D Correct answer Explanation Dividing by 1/2 is the same as multiplying by 2. So, 30 divided by 0.5 equals 60. Adding 10 to 60 results in 70. Common errors include dividing by 2 (getting 15) or misinterpreting the fraction.