We assume, that the number 50 is 100% - because it's the output value of the task. <span>We assume, that x is the value we are looking for. </span>If 100% equals 50, so we can write it down as 100%=50. <span>We know, that x% equals 20 of the output value, so we can write it down as x%=20. </span>Now we have two simple equations: 1) 100%=50 2) x%=20 where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that: 100%/x%=50/20 Now we just have to solve the simple equation, and we will get the solution we are looking for.
If the ball hit the ground it means that its height is equal to 0. In order to find the time after the ball <span>will hit the ground, we need to find the solution of the equation h(x)=0 which is different to 0.
