40 percent of what number is 28
The Correct Answer and Explanation is:
To find out what number 40 percent of equals 28, we can set up the equation as follows:
Let ( x ) be the unknown number. The equation can be represented as:
[
0.40 \cdot x = 28
]
To isolate ( x ), we can divide both sides of the equation by 0.40:
[
x = \frac{28}{0.40}
]
Calculating this gives:
[
x = 70
]
Thus, 40 percent of 70 is 28. To understand how this works in more detail, let’s break it down.
Understanding Percentages:
A percentage is a way to express a number as a fraction of 100. Therefore, 40 percent can be rewritten as a decimal:
[
40\% = \frac{40}{100} = 0.40
]
When we say “40 percent of a number,” we are essentially multiplying that number by 0.40. So in our case, we are looking for a number that, when multiplied by 0.40, results in 28.
The Calculation:
When we set up our equation, we recognize that to reverse the operation of multiplying by 0.40, we divide 28 by 0.40. This division tells us how many whole units make up 28 when only 40 percent is taken into account. The division can also be understood as scaling up from the partial amount (28) back to the whole (70).
Verification:
To verify our solution, we can multiply 70 by 0.40:
[
0.40 \cdot 70 = 28
]
This confirms that our calculation is correct. Thus, the answer is that 40 percent of 70 equals 28.