What percent of 36 is 90?

90/36*100%
  = 2.5*100%
  = 250%

90 is 250% of 36.

The  ans can be written as :
Let x be the percentage of 36 ie. X % of 36
which can be written as (x * 36)/100 = 90
                                        36x / 100 =  90
                                            36x = 90 * 100
                                            36x = 9000
                                                x = 9000 /36
                                                x = 250

So the correct ans is 250% of 36 = 90

40%
36/90=.40
.40=40%
Check
90x.40=36
Correct

90% into decimal  is 90/100 = .9
36 * .9 = 32.4

Check
32.4 / 36 = .9 * 100 = 90%