To solve this problem, we set up a proportion. We are looking for the number which is 25% of 80, thus we set up 25/100 = x/80. We set up this proportion so that the "wholes" are on the same side of the fraction. Then we simplify the left side (since 25/100 = 1/4) to make our arithmetic a bit easier. We now have 1/4 = x/80. Cross multiplying, we get 80 = 4x. Dividing both sides by 4, we get x = 20.

25% = 25/100

\(\displaystyle \frac{25}{100}=\frac{x}{80}\)

\(\displaystyle \frac{1}{4}=\frac{x}{80}\)

\(\displaystyle (1)(80) = (4)(x)\)

\(\displaystyle \frac{80}{4}=\frac{4x}{4}\)

\(\displaystyle 20=x\)

\(\displaystyle 14\%=\frac{14}{100}\)

Divide numerator and denominator by 2 and you get \(\displaystyle \frac{7}{50}\), so 7 is 14% of 50.

\(\displaystyle Inventory = 500-15-185=300\)

\(\displaystyle Percentage=\frac{300}{500}=.6=60\%\)

To find 35% of 200, we just need to multiply

 \(\displaystyle (200)(0.35)\)

This gives us our answer, 70. Alternatively, we could realize instinctively that 35% of 100 is 35, and then double it to get the same answer.

First, write 64% as a decimal. Just move the decimal point of 64% two digits to the left and then eliminate the % so that we get 0.64.  Thus, 64%=0.64. Then multiply that 0.64 by 86

\(\displaystyle 0.64\times 86=55\)

So 55 is 64% of 86.

It takes Bob and Wendy 8 hours to clean the entire house, for a total of 16 man-hours. This means that one hour of cleaning by one person will clean \(\displaystyle \frac{1}{16}\) of the house, or 6.25%. Thus, Wendy can clean 25% of the house by herself in 4 hours.

Convert 34% to a decimal: 0.34

Multiply 0.34 by 492: 167.28

Round to the nearest tenth: 167.3

To find a part of the whole number, you multiply the percentage in decimal form against the whole number. The first step is to convert the percentage into a decimal, \(\displaystyle \small 30\%\) to \(\displaystyle 0\small .30\). Then multiply the decimal against the whole number,  \(\displaystyle 0\small .30\times100 = 30\). 

To find the part of the whole, first convert the percentage to a decimal, \(\displaystyle \small 75\%\) to \(\displaystyle 0\small .75\), then multiply the decimal against the whole number given, \(\displaystyle 0\small .75\times 200\), resulting in \(\displaystyle \small 150\). Alternatively, we know that \(\displaystyle \small 75\%\) is equal to \(\displaystyle \small \frac{3}{4}\) , so we could divide the whole number, \(\displaystyle \small 200\),  into four equal parts, which would be \(\displaystyle \small 50\). Since we need  \(\displaystyle \small \frac{3}{4}\) (three quarters), we multiply \(\displaystyle \small 50\) \(\displaystyle \small \times4\), resulting in \(\displaystyle \small 150\). 

If \(\displaystyle 0\small .304\) of the student body is female, this is equivalent to \(\displaystyle \small 30.4\%\).  Since \(\displaystyle \small 100\%\) is the whole, \(\displaystyle \small 100\% - 30.4\% = 69.6\%\). Thus \(\displaystyle \small 69.6\%\) is not female.

Alternatively, if \(\displaystyle 0\small .304\) is not male, then the rest must be male, so \(\displaystyle \small 1 - 0.304 =\) \(\displaystyle \small 0.696\). Then we can convert that decimal to a percentage, \(\displaystyle \small 69.4\%\).