Set? Are you missing part of the question
When the ball hits the ground, the height is 0.
0 = 100 - 16t²
0 = (10 - 4t)(10 + 4t)
0 = 10 - 4t or 0 = 10 + 4t
4t = 10 or -4t = 10
t =
or t = 
Time cannot be negative (unless you have a time machine) so disregard 
Answer: t =
= 2.5 seconds
To solve this question, you need to first look at the total amount of birds and then at the percentage of the blue jays that fed on the bird feeder out of all the other birds.
To calculate the total you add them all together:
59+68+12+1 = 140 birds
Then the percentages of the blue jays that fed on his bird feeder are:
59/140 *100 = 42.143%
You want to see how many blue jays we can expect to see out of 300 birds.
So you divide 300 by 100 to see what 1% is = 3 birds
Then you multiply this amount (1% = 3 birds) by 42.134% which is the percentage of blue jays we can expect to see out of the 300 birds.
3*42.134 = 126.43
You round this off to 126 because you cant expect to see half a bird. Even if the answer had been 126.9, you would have rounded it of to 126 because no matter how close it is to the next whole number; you either have a whole bird or you don't.
Final Answer = 126
Answer:
900 million.
Step-by-step explanation:
It's estimated that there are 900 million dogs in the world, as of 2018.
100 cm = 1m
To find 60 000cm, multiply by 600 :
60 000 cm = 600m
To convert from m to km, divide by 1000 :
600m ÷ 1000 = 0.6km