Answer:
7.9
Step-by-step explanation:
Assuming you mean y = 200 - 16t^2, we have all the required information needed to solve this problem. The y-value is the height of the building and the t-value represents the number of seconds after the shoe fell off.
Since we are trying to solve <em>for t</em>, we will be using our y-value. The problem states that we landed on a building with a height of 31 feet. We can plug this into the y-value, since that is what y is defined as (the height of the building).
Now we have:
31 = 200 - 16t^2
We can solve this to find t:
-169 = -16t^2
169 = 16t^2
10.5625 = t^2
3.25, -3.25 = t
We have found two answers for t. However, the negative value is not a solution because we can not have a negative number of seconds. Thus, 3.25 is the only value of t which works for this problem.
Since t is the value we are trying to find, we have our answer. The shoe hits the building after 3.25 seconds.
Answer:
%
Step-by-step explanation:
Probability is found by first forming a fraction where the numerator represents the number of desired outcomes and the denominator represents the total number of outcomes. In this case, the desired outcomes is the amount of times the coin lands on heads (9) and the total outcomes is the number of times the coin is tossed (20):

Divide numerator by denominator to get a decimal: 9÷20= 0.45
Multiply the decimal by 100 to get a percent: 0.45 x 100 = 45%
The answer would be that Mario finished his homework at 3:55