Question

What is the number if 6/7 of 28 is equal to 30% of that number

Answer 1

Answer:

80

Step-by-step explanation:

Let the number be x

6/7 X 28/1 = 30/100x

x=80 the number is 80

Answer 2

Answer:

80

Step-by-step explanation:

$\bold{STEP\ 1:}\\\\\dfrac{6}{7}\ of\ 28=\dfrac{6}{7\!\!\!\!\diagup_1}\cdot28\!\!\!\!\!\diagup^4=(6)(4)=24\\\\\bold{STEP\ 2:}\\\\_{\bold{METHOD\ 1}}\\\\p\%=\dfrac{p}{100}\to30\%=\dfrac{30}{100}=0.3\\\\x-\text{a number}\\\\0.3x=24\qquad\text{divide both isdes by 0.3}\\\\\dfrac{0.3x}{0.3}=\dfrac{24}{0.3}\\\\x=80$

$_{\bold{METHOD\ 2}}\\\\\begin{array}{ccc}30\%&-&24\\\\100\%&-&x\end{array}\qquad\text{cross multiply}\\\\\\(30)(x)=(100)(24)\\\\30x=2400\qquad\text{divide both sides by 30}\\\\\dfrac{30x}{30}=\dfrac{2400}{30}\\\\x=80$

$_{\bold{METHOD\ 3}}\\\\\begin{array}{cccc}30\%&-&24&\text{divide both sides by 3}\\\\\dfrac{30\%}{3}&-&\dfrac{24}{3}\\\\10\%&-&8&\text{multiply both sides by 10}\\\\(10\%)(10)&-&(8)(10)\\\\100\%&-&80\end{array}$