1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
IRINA_888 [86]
2 years ago
5

4) A boat covers 25km upstream and 44km downstream in 9 hours. Also it covers 15 km upstream and 22 km downstream in 5 hours. Fi

nd the speed of boat in still water.
Mathematics
1 answer:
Vera_Pavlovna [14]2 years ago
3 0

Answer:

Speed of boat in still water=8km/hr

Speed of stream=3km/hr

Step-by-step explanation:

Speed of boat in still water=x km/hr

Speed of stream=y km/hr

Speed of upstream=x-y km/hr

Speed of downstream=x+y km/hr

Let 1/(x-y)=a and 1/(x+y)=b

Time to go 25km up and 44 down=9

25a+44b=9----->(1)

Time to go 15km up and 22km down=5

15a+22b=5------>(2)

(2) × 2=> 30a+44b=10------>(3)

(3)-(1)=>5a=1

a=1/5

1/(x-y)=1/5

x-y=5---->(4)

Putting a=1/5 in (1),

5+44b=9

44b=4

b=1/11

1/(x+y)=1/11

x+y=11---->(5)

(4)+(5)=>2x=16

x=8

y=3

Speed of boat in still water=8km/hr

Speed of stream=3km/hr

You might be interested in
What is the location of the point on the number line that is 3/7 of the way from A=6 to B=20?
-Dominant- [34]

Answer:

12

Step-by-step explanation:

20-6=14 (Distance between points) then 14*3/7=6.

3/7 of the distance from A=6 to B=20 is 6. Thus, we find the point that is

3/7 of the distance from A=6 to B=20 by adding 6 to 6.

6+6= 12

Therefore, the point that is

3/7 from A=6 to B=20 is 12.

7 0
2 years ago
Find the length of diagonal HJ. Round to the nearest hundredth.
Alisiya [41]

Answer:

The length of the diagonal HJ is 10.82 units

Step-by-step explanation:

* Lets revise the rule of the distance between two points

- d=\sqrt{(x_{2}-x_{1})^{2}+(y_{2}-y_{1})^{2}}, where

 (x_{1},y_{1}) and (x_{2},y_{2}) are the two points

* Lets use this rule to find the length of the diagonal HJ

∵ The coordinates of point H are (-4 , 3)

∵ The coordinates of point J are (5 , -3)

∴ x_{1}=-4 and x_{2}=5

∴ y_{1}=3 and y_{2}=-3

- Lets find the length of the diagonal HJ by using the rule above

∴ HJ = \sqrt{(5-(-4))^{2}+(-3-3)^{2}}=\sqrt{(5+4)^{2}+(-6)^{2}}

∴ HJ = \sqrt{(9)^{2}+36}=\sqrt{81+36}=\sqrt{117}=10.81665

∴ HJ = 10.82

* The length of the diagonal HJ is 10.82 units

7 0
3 years ago
What equation best models this data? (Use y to represent the population in millions, and t to represent the year, assuming that
lapo4ka [179]

Answer:

y = 2.31x + 309.35

Step-by-step explanation:

Whenever you are checking for a best fitting equation you want to check if it has a constant slope.  If it does then the relation is linear and super easy.

So, since the t values are increasing by the same amount you want to see if the y values are  too.  And they are, each population entry is increasing by 2.31, this is the slope.  

Also, keep in mind you can caluclate slope with the equation \frac{y_2-y_1}{x_2-x_1}  here x is replaced by t though.

Now, since we know it's linear and we know the slope we can find the equation with the formula  y - y1 = m(x - x1) where again, x is replaced by t and m is the slope 2.31

I am just going to use the first point.  so x1 = t1 = 0

y - 309.35 = 2.31(x-0)

y = 2.31x + 309.35

Let me know if there was something you didn't understand.  

5 0
2 years ago
A rocket is launched from a tower. The height of the rocket, y in feet, is related to the time after launch, x in seconds, by th
Anni [7]

Answer: The rocket will reach its max after 4 seconds

Step-by-step explanation:

Hi, to find the maximum height, we have to set the first derivative of the equation equal to zero.

y=-16x^2+128x+136

0 = (2)-16x +128  

0= -32x+128

Solving for x:

32x = 128

x = 128/32

x = 4 seconds

The rocket will reach its max after 4 seconds

Feel free to ask for more if needed or if you did not understand something.

7 0
2 years ago
What is the ratio of daises to all the flowers in the vase?
ddd [48]

Answer: Do you have the original ration so we can simplify it then??

Step-by-step explanation:

3 0
3 years ago
Other questions:
  • What is a description of Morokweng Crater, South Africa (Africa)
    14·1 answer
  • It takes Maria 59 minutes to walk to her friends house 1 2/3miles away. What is her walking pace in mph?
    5·1 answer
  • How do you solve this?
    6·1 answer
  • What is 2432 divided by 102344
    15·2 answers
  • A driver descends 24 feet in 1 minute. What is his rate of descent in feet per second?
    7·1 answer
  • Five times the difference of twice a number and eleven is negative twenty-five. Find the number.
    11·1 answer
  • The equation for a line is 4x -3y=24. What is the slope of the line?
    14·2 answers
  • Harper surveyed 380 of the students in her school about their favorite color. 57 students said their favorite color was red. Wha
    11·1 answer
  • How many ninths are in 5 wholes??? <br>Answer correct, please do quickly!!!<br>TY:)​
    8·2 answers
  • WHY IS NOBODY HELP ME I GOT 2 OTHER QUESTIONS POSTED AND NOBODY ANSWERED ME
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!