The answer is infinitely many solutions

If you divide the 2nd equation by 3, you get the first equation, meaning they are identical. That means that any value of x will be true, which means there are infinite solutions

3 0

3 years ago

It takes 5 hours for a boat to travel 25 miles upstream. The same boat can travel 30 miles downstream in 2 hours. Find the speed

loris [4]

Answer:

so 5 miles upstream and 15 miles downstream

Step-by-step explanation:

25/5=5

30/2=15

3 0

2 years ago

Determine the average speed of the current in a river if a boat moves at 20 miles/hour in still water and takes 3 hours to trave

Taya2010 [7]

The speed of the current in a river is 6 miles per hour

Solution:

Given that,

Speed of boat in still water = 20 miles per hour

Time taken = 3 hours

Distance downstream = 78 miles

To find: Speed of current

If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then:

Speed downstream = (u + v) km/hr

Speed upstream = (u - v) km/hr

Therefore, speed downstream is given as:

$\text{ speed downstream } = \frac{distance}{time} = \frac{78}{3}\\\\\text{ speed downstream } = 26 \text{ miles per hour }$

We know that,

Speed downstream = (u + v)

26 = 20 + v

v = 26 - 20

v = 6 miles per hour

Thus speed of the current in a river is 6 miles per hour

3 0

3 years ago

If y has moment-generating function m(t) = e 6(e t −1) , what is p(|y − µ| ≤ 2σ)?

Lostsunrise [7]

Since $\mathrm M_Y(t)=e^{6(e^t-1}$ , we know that $Y$ follows a Poisson distribution with parameter $\lambda=6$ .

Now assuming $\mu,\sigma$ denote the mean and standard deviation of $Y$ , respectively, then we know right away that $\mu=6$ and $\sigma=\sqrt6$ .

So,

$\mathbb P(|Y-\mu|\le2\sigma)=\mathbb P(6-2\sqrt6\le Y\le6+2\sqrt6)=\dfrac{66366}{175e^6}\approx0.940028$

6 0

3 years ago