If the average of 6x and 8y is greater than 100, and x is twice y, what is the least integer value of x ? Pick:
A) 22	B) 20	C) 21	D) 23	E) 24
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 6x and 4x is greater than 100. Average of 6x and 4x is 5x. So,   5x &gt; 100   x &gt; 20   Answer : 208 /2= 
<gadget id="calculator">8 /2</gadget>
<output>4</output>
4x   Now average of 6x and 4x is greater than 100. Average of 6x and 4x is 5x. So,   5x &gt; 100   x &gt; 20   Answer : 20
<result>B</result>
If the average of 6x and 8y is greater than 100, and x is twice y, what is the least integer value of x ?