Hello!
First, we must convert 1/5 to a decimal by dividing the numerator by the denominator, and then we will convert the decimal to a percentage by multiplying the decimal by 100. Finally, we will subtract that percentage from 100%.
I know that's a lot to take in! :D
1 ÷ 5 = 0.2
0.2 × 100 = 20%
100% - 20%
We can double check by converting 4/5 to a percentage:
4 ÷ 5 = 0.8
0.8 × 100 = 80%
That means we're right!
Your answer is:
80% of the club did NOT sign up for the workshop!