Round 258,177 to the nearest hundreds thousand

What is the smallest integer n such that n\sqrt{2} is greater than 20

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?