30% of what number is 150? A. 500 B. 50 C. 45 D. 200
The Correct Answer and Explanation is:
To find 30% of what number is 150, we can set up the equation:0.30×X=1500.30 \times X = 1500.30×X=150
To solve for XXX, divide both sides of the equation by 0.30:X=1500.30=500X = \frac{150}{0.30} = 500X=0.30150=500
Correct answer: A. 500
Explanation
Understanding percentages is essential in everyday life and especially in solving problems involving part-to-whole relationships. In this question, we are given a percentage and a resulting value and asked to determine the original number. The question asks, “30% of what number is 150?” This means that 150 is 30% of some unknown number.
Let’s break it down. The word “of” in math typically indicates multiplication. Therefore, 30% of a number is the same as multiplying that number by 30%. First, convert the percentage into a decimal. To do this, divide 30 by 100 which equals 0.30. Now we rewrite the problem using a variable for the unknown number:0.30×X=1500.30 \times X = 1500.30×X=150
Now we solve for XXX. This is a basic algebraic equation where you want to isolate the variable. To do that, divide both sides of the equation by 0.30:X=1500.30X = \frac{150}{0.30}X=0.30150
When you divide 150 by 0.30, the result is 500. This means 150 is 30% of 500. You can check your work by multiplying:0.30×500=1500.30 \times 500 = 1500.30×500=150
Since this is true, our answer is verified.
This type of question is a classic example of reverse percentage problems, where you are given the part and the percentage and need to find the whole. It’s especially useful in budgeting, sales tax calculations, or interpreting discounts. By mastering this type of problem, you gain the ability to quickly analyze and understand proportions in real-world situations. The correct choice among the options is A. 500.
