<span>When order does not matter you use what is called n choose k formula
n!/(k!(n-k)!) where n is the number of things to choose from and k is the number of choices made, in this case:
20!/(4!(20-4)!)=4845</span>
15 x 1.59 = 23.85
Her order is between 20 euros and 34.99 euros. Therefore, she gets 2.5% discount.
2.5 x 23.85/ 100 = 0.60
That means she gets approximately 60 cents off her order.
Answer:
$3.90
Step-by-step explanation:
78 cents/lb * 5 lb = (78*5) cents = 390 cents (the pound labels divide out)
But 390 cents = $3.90
Answer:
Equation of parabola: 8*(y - 2) = (x - 3)^2
or
y = (1/8)*(x - 3)^2 + 2
Step-by-step explanation:
focus at (3,4) and its directrix y = 0.
Focus equation: (h, k + c) = (3, 4)
Directrix equation y = k - c = 0
so h = 3, k + c = 4, k - c = 0
Solve the system : k + c = 4 and k - c = 0
add the equations together: k + c + k - c = 4 + 0
2k = 4
k = 2
so k + c = 4, 2 + c = 4, c = 2
4c (y - k) = (x - h)^2
4*2 *(y - 2) = (x - 3)^2
8*(y - 2) = (x - 3)^2
