You can
put this solution on YOUR website!Normal = x
When 5 students failed = x-5
Total = 500
Increased by 5 = +5

500[(x)-(x-5)]=5[(x)(x-5)]

Facotr the quadratic equation:
(x+20)(x-25)
x=-20 and x= 25
Remove the negative. And:
Hence, the total number of students were 25.
Paul.