Question

out of 600 students of school, 120 goes for Princy find the percentage of students who did not go for Princy

Answer 1

$total \: student = 600 \\ not \: go \: for \: picnic = 600 - 120 = 480 \\ \% = \frac{480 \times 100}{600} = 80\%$

Answer 2

No of students who didn't go for picnic= 600-120= 480.
Hence Percentage of students who didn't go for picnic= (480/600)/100.
= 80%.
Hope it helps.