We must find UNIQUE combinations because choosing a,b,c,d... is the same as d,c,b,a...etc. For this type of problem you use the "n choose k" formula...
n!/(k!(n-k)!), n=total number of choices available, k=number of choices made..
In this case:
20!/(10!(20-10)!)
20!/(10!*10!)
184756
Answer:
In order to maximize the last equation we can derivate the function in term of x and we got:
And setting this derivate equal to 0 we got:
And solving for x we got:
And for this case the value that maximize the profit would be x =95 and the corresponding profit would be:
Step-by-step explanation:
For this case we have the following function for the profit:
And we can rewrite this expression like this:
In order to maximize the last equation we can derivate the function in term of x and we got:
And setting this derivate equal to 0 we got:
And solving for x we got:
And for this case the value that maximize the profit would be x =95 and the corresponding profit would be:
Answer:
Her speed on the summit was 35 mph.
Step-by-step explanation:
Her speed on the summit was "x" mph while her speed while climbing was "x - 10" mph. The distance she rode uphill was 55 miles and on the summit it was 28 miles. The total time she explored the mountain was 3 hours. Therefore:
time uphill = distance uphill / speed uphill = 55 / (x - 10)
time summit = distance summit / speed summit = 28 / x
total time = time uphill + time summit
3 = [55 / (x - 10)] + 28 / x
3 = [55*x + 28*(x - 10)]/[x*(x - 10)]
3*x*(x - 10) = 55*x + 28*x - 280
3x² - 30*x = 83*x - 280
3x² - 113*x + 280 = 0
x1 = {-(-113) + sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 35 mph
x2 = {-(-113) - sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 2.67 mph
Since her speed on the uphill couldn't be negative the speed on the summit can only be 35 mph.
Answer:
The height is 6 unit
The base is 2 units.
Step-by-step explanation:The given rectangle has vertices (–4, 7), (–2, 7), (–2, 1), and (–4, 1).
Answer:
x = 11
y = 3
Step-by-step explanation:
In a parallelogram opposite sides are equal.
8x = 88
x = 88/8
x = 11
4y - 7 = y + 2
4y = y + 2 + 7
4y = y + 9
4y - y = 9
3y = 9
y = 9/3
y = 3
