For example
1>x>3
says x is less than 1 and greater than 3
Profit will be achieved when the money earned is greater than the money spent so,
336 + (n*12) = n*28 any subsequent units sold would result in profit
336 = 28n - 12n
336 = 16n
=> n = 336/16 = 21
21 units must be sold to draw even any more would result in profit
If 2 equations have the same y-intercept, they are overlapping, which means they have infinite solutions. So there is no way that 2 equations with the same y-intercept will have no solution. Thus your answer is: C)Never.
3|3
1
6|2
3|3
1
7|7
1
LCM = 2*3*7 = 42