Does anybody here know the metric system?

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 result of adding the system of equations? 2x+y=4 3x-y=6

1: 4 if the wew 35 surfboards at the beach how many were short boards?