Can anybody PLEASE help me with the question below?

Question

I am already done with the worksheet on the website below so could some kind person fill it out and put it in the answers area.
thankyou I just want to improve my knowledge in projectile motion
http://modeling.asu.edu/Modeling-pub/Mechanics_curriculum/6-2D%20comb/06_U6%20ws%203.pdf

Answer 1

Here's a hint: 1/2 a t^2 = 1/2 g t^2 = 5 t^2 = distance.

Or solve for t=sqrt(distance/5).

If you're at all interested in mathematics, start studying calculus as soon as possible - it's amazing what you can do with it. Don't let anyone tell you you have to be in college first.