Answer: 60 pages left.
Step-by-step explanation:
Let the number of pages in the book be x.
As per given, we have
of total book = 
Pages left = 240-180
= 60
Hence, 60 pages left.
That first one is correct there is no solution since they are parallel.
Note how angle GFE forms a right angle, which is 90 degrees.
Since the line cuts that angle into two smaller angles, intuitively, these angles add up to 90 degrees.
So, we can say that 2x + 3x = 90 (angle sum of right angle)
5x = 90
x = 18 degrees
