exam Maths Puzzle Numerical Ability

Could someone help me please? The problem is:
A ball is thrown upward from the roof of a building 100m tall with an initial velocity of 20m/s. When will the ball reach a height of 80m?

Read Solution (Total 0)

exam Other Question
Jill and Jack play basketball. In the first game, Jill had a foul shot average of 0.60(she made 12 or 20 shots), and Jack had a foul shot average of 0.50(he made 5 out of 10 shots) this is a multiplacation problem ,can you teel me if this is correct ,if not can you show me the right way
(3m-2n)
(3m)*(-2n^2 )
3*m*2*n^2
-6*m*n^2