If the average of 12x and 8y is greater than 200, and x is twice y, what is the least integer value of x ? Select the correct option
A) 20	B) 30	C) 40	D) 25	E) 35
Substitution can be used in the following way:   Always start with the equation: x = 2y. It is more straight forward to manage as compared to the inequality.   Substitute y = x/2, not the other way because you need to find the minimum value of x. So you can get rid of y.   Now go on to the inequality. So 8y = 8x/2 = 4x   Now average of 12x and 4x is greater than 200. Average of 12x and 4x is 8x. So,   8x &gt; 200   x &gt; 25   Answer : 258 /2= 
<gadget id="calculator">8 /2</gadget>
<output>4</output>
4x   Now average of 12x and 4x is greater than 200. Average of 12x and 4x is 8x. So,   8x &gt; 200   x &gt; 25   Answer : 25
<result>D</result>
If the average of 12x and 8y is greater than 200, and x is twice y, what is the least integer value of x ?