Can someone anyone help me with these two it’s a test and it’s due today help!

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

Over which interval is the graph of f(x) = x2 + 5x + 6 increasing?

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters