Question 851994
Let:
x - be the number
54x - 54 of a number
45x - 45 of a number

Since the correct answer (54x) wasn't found, instead the student found (45x) which is 36 less than the correct answer (54x) the equation goes:

45x=54x-36
36=9x
x=4

Therefore the number is 4 and 54 of 4 is, 216!

Hope that helpS!