All you have to do is multiply the l * w = Area
When you look at 26 ft and 15 ft, 21 ft and 10 ft, 29 ft and 18 ft, you'd know it wouldn't work since it's over 180.
So the dimensions of the ceiling are l = 20 ft; w = 9 ft
102 grams would be remaining after a total of 3 half lifes occur in 105 days
Convert all the equations to slope-intercept form:



Lines A, B and C have the same slope as the line 2y-4x=3, so they are parallel and don't intersect it.
Line D has another slope, so it intersects the line 2y-4x=3.
The answer is D.