Answer:
a) 35, b) 25, c) 60
Step-by-step explanation:
The number of girls is 10 more than the number of boys, so it's a good thing to choose a variable to represent the number of boys.
Number of boys: b
Number of girls: b + 10
Ratio of girls:boys is 7:5, so
"Cross multiply" to get
There are 25 boys. There are 10 more girls, so the number of girls is 35, and the total number of students is 60.
That's a packed classroom!
Given:
The power generated by an electrical circuit (in watts) as function of its current x (in amperes) is modeled by:
To find:
The current that will produce the maximum power.
Solution:
We have,
Here, leading coefficient is negative. So, it is a downward parabola.
Vertex of a downward parabola is the point of maxima.
If a parabola is , then
In the given function, a=-12 and b=120. So,
Putting x=5 in the given function, we get
Therefore, 5 watt current will produce the maximum power of 300 amperes.