Verified Answer :

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! :)

ok so 40% is also 40/100 so take 40/100 and get 2.5. times that by 60 and you get 150.