If you divide 30 by half and add ten what is the answer
The Correct Answer and Explanation is:
The correct answer to the riddle is 70.
This is a classic math riddle that often causes confusion due to its wording. The solution requires careful attention to the mathematical operations being described. The trick lies in the first part of the phrase, “If you divide 30 by half.”
Many people mistakenly interpret this as dividing 30 by the number 2. This would be described as “dividing 30 in half,” which results in 15. However, the question asks you to divide 30 by half. The numerical value of “half” is the fraction 1/2 or the decimal 0.5. Therefore, the first step of the calculation is 30 ÷ (1/2).
In mathematics, dividing by a fraction is the same as multiplying by its reciprocal. The reciprocal of 1/2 is 2/1, or simply 2. So, the calculation becomes 30 × 2, which equals 60. You can also think of it conceptually: how many halves are there inside of 30 whole units? Since each whole unit contains two halves, 30 units would contain 30 times 2, or 60 halves.
Once this first, most critical step is completed, the rest of the problem is straightforward. The question then asks you to “add ten” to the result. Taking the correct result from the division, which is 60, you perform the final calculation.
60 + 10 = 70.
Thus, by correctly interpreting the instruction to divide by the value of one-half and not the integer two, and then performing the simple addition, we arrive at the correct final answer of 70. The riddle serves as a great reminder of how important precise language is, especially in mathematics.
