20% of a number is 12.
what is the whole number?

Asurvey of 45 teens found that they spent an average of 25.6 hours per week in front of a screen (television, computer, tablet, phone, based on the survey’s sample mean, which value could be the population mean? 2.3 hours 27.4 hours 75.3 hours 41.5 hours

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4

Pls never taught i’m really confused and i rlly need