CAN SOMEONE ANSWER 4 AND SHOW YOUR WORK PLEASE AND THANK YOU

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

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?