Let x be the the maximum marks
First, you multiply x by 40%, and you get:
\(\frac{40}{100}x = 60\)
\(0.4x = 60\)
You move 0.4 to the other part. and since 0.4 was a multiplication, it become a division, so you get:
\(x = \frac{60}{0.4}\)
you divide, and you get:
\(x = 150\)
So, the full marks are 150 points.
Hope this Helps! :)