Answer:
Step-by-step explanation
- Let x be the number of adults and y the number of kids
We can then write this two equations :
x+y= 33
15x+7y= 311
- let's solve the two eaquations
to do that we should combine them both in a way that help us get rid of one of the variables.
Let's multiply the first equation by -7 to get rid of y by adding it to thr second equation
-7x-7y= -231
now add both equations .
15x+7y-7x-7y=311-231
we get : 8x = 80
as you notice y is gone and we get a classic easy equation to solve
x= 80/8
= 10
so the number of adults is 10
let's go back to the first equation ( x+y= 33) and replace x with 10
10+y= 33
y= 33-10
=23
let's check using the second equation :
(10*15)+(23*7) = 311
that is true
so :
- the number of adults is 10
- the number of kids is 23
Answer:
The rocket will take 4.5 seconds to reach its maximum height.
Step-by-step explanation:
The height of a missile t seconds after it has been fired is given by h=-4.9*t²+44.1*t
This function is a quadratic function of the form f (x) = a*x² + b*x + c. In this case a=-4.9, b=44.1 and c=0
To calculate how many seconds it will take for the rocket to reach its maximum height, I must calculate the maximum of the function. The maximum of a quadratic function is the vertex of the parabola. The x coordinate of the vertex will be simply:
. The y coordinate of the vertex corresponds to the function evaluated at that point.
In this case the x coordinate of the vertex corresponds to the t coordinate. In other words, by calculating the x coordinate of the vertex, you are calculating the maximum time t it will take for the rocket to reach its maximum height. So:

t=4.5
<u><em>The rocket will take 4.5 seconds to reach its maximum height.</em></u>
Answer:
22
the sixth number of them is the median
Answer:
Total no.of possible outcomes = 200 × 4 = 800
No.of favourable outcomes = 200 × 1 = 200
P (E) = no.of favourable outcomes / total no.of possible outcomes
= 200/800
= 1/4