21% were absent, if you divide 146 by 680 and multiply by 100, then round to the nearest whole number, you get 21
8c -c= 7c
7c+6=48
7c=42
c=6
CHECK:
8(6)-(6)+6=48
48-6=42
42+6=48
48=48
If the turn out of an event is to take place or not to take place only then, the sum of the probability of it taking place and not taking place is 1. If we represent the probability of it taking place by x then, the probability of it not taking place is equal to 1 - x.