Answer:
There are 8 in each stack.
Step-by-step explanation:
Divide 24/3=8.
Answer:
The top speed of William's boat was 45 mph
Step-by-step explanation:
Let
x -----> represent the rate of the boat in still water in mph
we know that
The speed or rate is equal to divide the distance by the time
speed=distance /time
time=distance/speed
<em>Downstream</em>
speed=(30+x) mph
distance=10 mi
time1=10/(30+x)
<em>Upstream</em>
speed=(x-30) mph
distance=2 mi
time2=2/(x-30)
The sum of the time downstream plus the time upstream must be equal to 16 minutes
Convert minutes to hours
![16\ min=16/60\ h](https://tex.z-dn.net/?f=16%5C%20min%3D16%2F60%5C%20h)
![\frac{10}{x+30} +\frac{2}{x-30}=\frac{16}{60}](https://tex.z-dn.net/?f=%5Cfrac%7B10%7D%7Bx%2B30%7D%20%2B%5Cfrac%7B2%7D%7Bx-30%7D%3D%5Cfrac%7B16%7D%7B60%7D)
Multiply by (x+30)(x-30) both sides
![10(x-30)+2(x+30)=\frac{16}{60}(x^2-900)\\10x-300+2x+60=\frac{16}{60}x^2-240\\12x-240=\frac{16}{60}x^2-240\\\frac{16}{60}x^2-12x=0](https://tex.z-dn.net/?f=10%28x-30%29%2B2%28x%2B30%29%3D%5Cfrac%7B16%7D%7B60%7D%28x%5E2-900%29%5C%5C10x-300%2B2x%2B60%3D%5Cfrac%7B16%7D%7B60%7Dx%5E2-240%5C%5C12x-240%3D%5Cfrac%7B16%7D%7B60%7Dx%5E2-240%5C%5C%5Cfrac%7B16%7D%7B60%7Dx%5E2-12x%3D0)
Multiply by 60 both sides
![16x^2-720x=0](https://tex.z-dn.net/?f=16x%5E2-720x%3D0)
Divide by 16 both sides
![x^2-45x=0\\x(x-45)=0](https://tex.z-dn.net/?f=x%5E2-45x%3D0%5C%5Cx%28x-45%29%3D0)
The solution is x=45\ mph
$25 ... 1 month (installments for a TV screen)
$900 ... x months
If you would like to know how many months will she take to pay a total of $900, you can calculate this using the following steps:
25 * x = 900 * 1 /25
x = 900 / 25
x = 36 months /12
x = 3 years
Result: 3 years equals to 36 months.
Answer:
18
Step-by-step explanation: