MATH WHAT IS THIS!!!
Four people need to cross a dark river at night.They have only one torch and the river is too risky to cross without the tourch. if all people cross simultanoesly then torch light wont be sufficient.Speed of each person of crossing the river is different.cross time for each person is 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the river ?

Answers

Answer 1

Answer:

17 minutes    i had this same answer and question 2day, so ur lucky.

Step-by-step explanation:

The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.

To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.

1 and 2 go cross

2 comes back

7 and 10 go across

1 comes back

1 and 2 go across (done)

Total time = 2 + 2 + 10 + 1 + 2 = 17 mins

Answer 2

Answer:

17 minutes

Step-by-step explanation:

Let A be the person who takes 1 min,

B who takes 2 mins, C who takes 7 mins and D who takes 10 mins

A and B cross the river in 2 mins, A comes back in 1 min

C and D cross the river in 10 mins, B comes back in 2 mins

A and B cross the river in 2 mins

Total time:

2 + 1 + 10 + 2 + 2 = 17 minutes


Related Questions

Match each equation with its graph

Answers

Answer:

A--> D

B-->A

C--> C

D-->B

I really need help with this :((

Answers

Answer:

Step-by-step explanation

The two other forms are written form and expanded from. That first blank is for written from and the answer is four and eight-hundred twenty-sixth thousandths. For the other ones i think for the first blank it is 4 then 8 then 20 and then 6.

Do not do Number 3 or 2!Please help! I need them in complete sentences! I will award Brainliest and answer any questions you have just please help.

Answers

Answer:

2) Only solar because u are near the moon lool

3) i think the same

1-4)There is, however, one side of the moon that never faces Earth head-on. The moon completes a full, 360-degree orbit around our planet every 27.32 days . That's about as long as it takes the moon to finish a single rotation on its own axis. Taken together, those two factors explain why only one side of the moon is ever oriented toward us and about 41 percent of the lunar surface is never visible to Earth-bound stargazer.

Eevery lunar day lasts for 29.5 Earth day

Smh, what is this. If you answer this, please add a prove it statement. Thank you.​

Answers

28 slices
10 1/2 divided by 3/8 is 28
28 times 3/8 equals 10 1/2

-2 x (-7) =
24 divided by (-3) =

Answers

Answer:

1)  14

2) -8

Step-by-step explanation:

-2 × (-7) = 14

24 ÷ (-3) = -8

There different ways to think about 1 3/8- 1/1/8. Select three ways to find it

Answers

Answer:

1. 1 3/8- 1 /1/8

2. 11/8- 9/8

3. 1 3/8- 9/8

Step-by-step explanation:

4: From each corner of a square table a quarter of a circle is cut off. The sides of the square table are 5 cm. Each of the circular parts have a radius of 1 cm. Find the area of the shaded part of the square table in cm2.

Answers

The figures were not drawn to scale.

Answer: (25 – π)

Justin did push-ups every weekend this week he did a push ups on Monday on Tuesday on Wednesday Sims push-ups on Thursday and a push-ups on Friday find the mean number of push-ups ​

Answers

Mean is just another name for average. To find the mean of a data set, add all the values together and divide by the number of values in the set. The result is your mean!

Answer:

Step-by-step explanation:

You have ten pigeons. You want to give these pigeons away to some of your friends. The first friend picks a number of pigeons of her choice for herself. After that you give away the remaining pigeons to the rest of your friends. If you give each of them 3 pigeons, 5 are left and if you give each of them 5 pigeons, 3 are left. How many pigeons did your first friend choose for herself?

Answers

Answer:

2

Step-by-step explanation:

The following data points represent the volume
of gas in each race car driver's tank (in liters).
4,5, 13, ?
If the mean of the data set is 7 L, find the
missing volume of gas.

Answers

Answer:

The missing volume of gas is 6 liters

Step-by-step explanation:

The following data points represent the volume  of gas in each race car driver's tank (in liters):

4,5, 13, ?

Let the missing value be x

Data : 4,5,13,x

[tex]Mean = \frac{\text{Sum of all observations}}{\text{No. of observations}}[/tex]

[tex]7 = \frac{4+5+13+x}{4}[/tex]

[tex]7 \times 4=4+5+13+x[/tex]

28=22+x

28-22=x

6=x

Hence The missing volume of gas is 6 liters

Answer:

6

Step-by-step explanation:

Khan Academy

Solve using substitutions! Help w this question please!!

Answers

I hope this helps you

The center of the circle is (3,2). The circle passes through (7,6). What is the radius ?

Answers

Answer:

Step-by-step explanation:

i’m not sure but add them

Answer:

square root of 32

Step-by-step explanation:

you have to take center and the point it passes and solve them

Find the hypotenuse of a right triangle with the side length of 7 and an angle of 64 degrees.

Answers

It’s 24 with equals than 37 plus 8

Answer:

16.0 (to 3 s.f.)

Step-by-step explanation:

Please see the attached picture for full solution.

The average cost c (in dollars) to manufacture x t-shirts is given by the function c=7x+325x. Express the number of t-shirts in terms of the average cost. X=

Answers

Answer:

[tex]x=\dfrac{325}{c-7}[/tex]

Step-by-step explanation:

The average cost c (in dollars) to manufacture x t-shirts is given by the function:

[tex]c=\dfrac{7x+325}{x}[/tex]

We are required to express the number of t-shirts in terms of the average cost.

First, we cross multiply

cx=7x+325

Bring the terms containing x to the left hand side

cx-7x=325

Factorize out x

x(c-7)=325

Divide both sides by c-7

[tex]x=\dfrac{325}{c-7}[/tex]

Therefore, the number of t-shirts, x in terms of the average cost, c is:

[tex]x=\dfrac{325}{c-7}[/tex]

solve 25+8m =73 M=....​

Answers

Answer:

25+8m=73

We move all terms to the left:

25+8m-(73)=0

We add all the numbers together, and all the variables

8m-48=0

We move all terms containing m to the left, all other terms to the right

8m=48

m=48/8

m=6

Answer:

[tex]m = 6[/tex]

Step-by-step explanation:

[tex]25 + 8m = 73 \\ 8m = 73 - 25 \\ 8m = 48 \\ \frac{8m}{8} = \frac{48}{8} \\ m = 6[/tex]

Find the mean of the numbers below.
5, 10, 15, 20, 1, 2, 2, 1

Answers

Answer:

7

Step-by-step explanation:

used a calculator

A piepie is divided into 2020 equal pieces. GlennGlenn and SophieSophie each ate one fourth 1 4 of the piepie on MondayMonday. The next​ day, SophieSophie ate one fifth 1 5 of the piepie that was leftover. How many of the pieces of the original piepie ​remain? Explain your reasoning. ​Together, GlennGlenn and SophieSophie ate one fourth 1 4 ​piece(s) on MondayMonday​, and SophieSophie ate one fifth 1 5 ​piece(s) the next day. To find the number of pieces that​ remain, add these numbers to the total number of pieces.​ So, 0.450.45 pieces of the original piepie remain.

Answers

Answer:

Pieces remaining =  1 - (1/4 + 1/4) - (1/2 x1/5) = 1/2 - (1/2 x1/5) = 1/2 - 1/10 = 4/10

Therefore, 4/10 x 20 = 8 pieces.

Step-by-step explanation:

Sophie ate 1/4 = 5 pieces

Glenn ate 1/4 = 5 pieces

Remaining pieces = 20 - 5 - 5 = 10 pieces

On Monday, Sophie ate = 1/5 x 10 = 2 pieces

Therefore, remaining pieces = 10 - 2 pieces = 8 pieces

Sophie and Glenn consumed half of the pie the first day.  This is equal to 10 pieces.  The remaining pieces will be 10.  If, on Monday, Sophie ate 1/5 of 10 pieces, representing 2 pieces, the number left over is 10 Minus 2, which equals 8 pieces.

What is the solution to this system of equations graphed?

Write your answer as an ordered pair, for example (-4,5).

SEE PICTURE BELOW

Answers

Answer: (4,2)

Step-by-step explanation:

You can find the solution to a systems of equations graph by finding the point where the two lines intersect. In this case, they intersect at (4,2).

what’s the answer to this?

Answers

Answer:9

Step-by-step explanation:because when we add 7+7+6+6=26 then we will going to 35-26= 9 im not sure so don’t hate me if it was wrong

one hundred fifty moviegoers were surveyed, 20% said they would recommend the movie they just saw. how many of the moviegoers said they recommend the movie?​

Answers

Answer:

30

Step-by-step explanation:

150/100 = 1.5

1.5 is 1% of 150

20% of moviegoers recommend the movie

1.5 times 20 = 30

Which statement describes the relationship, if any, that exists between triangle KLM and triangle NPQ? Triangle L K M. Side K L is 16, L M is 22, K M is 12. Triangle P N Q. Side P N is 8, N Q is 6, P Q is 11. Angles L and P are congruent, Q and M are congruent, K and N are congruent.

Answers

Answer:

Its B I think

Step-by-step explanation:

Answer:

b

Step-by-step explanation:

Find out six rational numbers lying between -4/8 and -3/4

PLEASE HELP........ REALLY URGENT.... NEED TO SUBMIT NOW.........

Answers

ANSWER:

-17/32, -18/32, -19/32, -20/32, -21/32, -22/32

EXPLANATION:

-4/8 and -3/4

-4*4/8*4 and -3*8/4*8

-16/32 and -24/32

There are 8 numbers between -16/32 and -24/32. You can write any six of it.

Please help meeeee
What are the key aspects of the graph of f(x) = x^2-b^2
where b is a real number?

Answers

Answer:

the graph has opposite x intercepts of b and -b. the graph has y intercepts at –b². the graph of the function symmetrical about the y-axis.

Step-by-step explanation:

Find the slope of the line passing through the poin (- 3, 7) (2, - 6)

Answers

Answer:

[tex] \frac{13}{ - 5} [/tex]

Step-by-step explanation:

[tex] \frac{y1 - y2}{x1 - x2} \\ \frac{7 - ( - 6)}{ - 3 - 2} \\ \frac{7 + 6}{ - 5} \\ = \frac{13}{ - 5} [/tex]

Answer:

-2.6

Step-by-step explanation:

Slope or gradient is the ratio of the vertical (y axis) and horizontal distances (x axis) between two points on a line.

It should be noted that it is defined as zero if the line is horizontal, but undefined if it is vertical.

Given:

Coordinates (- 3, 7) (2, - 6)

y1 = 7, y2= -6, x1= -3, x2=2

Slope : ∆ y/ ∆ x

= (y2 - y1 )/ (x2 - x1)

= (-6 - (7))/ (2 - (-3))

= (-13)/(5) = -13:5= -2.6

which rational number does not have a reciprocal

Answers

Answer:

the rational numbers that doesn’t have a reciprocal are [math]0 [/math] (which can also be expressed as [math]\frac {0} {x}, x \neq 0 [/math] ), and any number of the form [math]\frac {x} {0} [/math].

Step-by-step explanation:

Four bags of peaches weigh 5.6 pounds, 3.9 pounds, 4.9 pounds, and 6.2 pounds.
What is the median weight of the bags?

Answers

The answer is 5.25

First, you need to list all of the numbers from least to greatest. Then, you remove the sides (first 3.9 and 6.2 being the least and the greatest numbers). You then have 4.9 and 5.6 so you need to add them together (getting 10.6) and divide your answer by 2 (getting 5.25).

Hope I helped and good luck :)

Lesson Check
Choose the correct answer.
5. Greg has 27 toy trucks. He divides them into
3 equal groups. How many toy trucks are in
each group?

Answers

There are 9 toy trucks in each group.

27 divided by 3 is 9. Therefore when you divide the trucks up in EQUAL groups the answer has to be 9.

You are holding a kite string in your hand. The angle of elevation from your hand to the kite is 44º and the distance to the kite is 250 feet.
Your hand is 5 feet above the ground. How high is the kite? Round your answer to the nearest tenth of a foot.
feet

Answers

243.6 because sin 53= x /300 so, 300 times sin 53 =239.59065 and then add 4

Which number line shows the solutions to n<-3

Answers

Answer:

[In Picture]

Step-by-step explanation:

There are no given options.

However, I am able to recreate the best answer for the question given.

There would be arrow going to the left from -3. The arrow will include all numbers less than -3.

Since there is a less than sign, the circle at the beginning of the arrow is open.

Choose the option that closely matches the line shown.

The number line is the representation of numbers in real order.

The difference between the consecutive numbers in a number line is always positive.

The number line of n < - 3 is n less than -3.

The graph of the number line is given below.

What is a number line?

It is the representation of numbers in real order.

The difference between the consecutive numbers in a number line is always positive.

We have,

n < - 3

This is read as,

n is less than -3.

The graph of the number line is given below.

Thus,

The number line of n < - 3 is n less than -3.

The graph of the number line is given below.

Learn more about number line here:

https://brainly.com/question/13425491

#SPJ5

tan(-20°) = _____. -tan 20° tan 20° tan (-160°) -tan 160°

Answers

Answer:

-tan 20

Step-by-step explanation:

They have the same answer when typed in a calculator

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