Answer:
200 muffins
Step-by-step explanation:
The selling price of each muffin = $2
The cost price of each muffin = $1.40
The price of electricity = $120
If the number of muffins that Jenny sells in a day is x, then, Jenny's total cost in a day is:
120 + (1.4 * x) = 120 + 1.4x
and the total sales earnings in a day for x muffins will be:
2 * x = 2x
To break even, the total costs in a day must equal to the total earnings. That is;

Solving this:

She must sell 200 muffins in a day to break even.
If the half-life is t, then every t days, the amount of the radioactive isotope will be cut in half.
(1/2)^(number of half-lives) = 3%
number of half-lives = ln(0.03) / ln(0.5)
This gives the number of half-lives as 5.06.
Then 300 days = (5.06)(length of 1 half-life)
length of 1 half-life = 300 / 5.06 = 59.29 days
Answer:
X Y
1 5
4/5 4
2/5 2
Step-by-step explanation:
y=5x
We we know y we need to solve for x
X Y
5
4
2
Let y =5
5 = 5x
Divide by 5
5/5 =5x/5
1=x
Let y =4
4 = 5x
Divide by 5
4/5 =5x/5
4/5=x
Let y =2
2 = 5x
Divide by 5
2/5 =5x/5
2/5=x
X Y
1 5
4/5 4
2/5 2
Answer:
1.36 miles per min
Step-by-step explanation:
Answer:
Option B. 1.8 seconds
Step-by-step explanation:
h=-16t^2+56t+1
This is a quadratic equation, and its graph is a parabola
h=at^2+bt+c; a=-16, b=56, c=1
Like a=-16<0 the parabola opens downward, and it has a maximum value (height) at the vertex, at the abscissa:

Replacing the known values:

Approximately 1.8 seconds.
Answer: It takes approximately 1.8 seconds the airplane to reach its maximum height.