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3 years ago

A boat makes a 120-mile trip downstream in 3 hours but makes the return trip in 4 hours. What is the rate of the current?

2 answers:

8 0

With the current 40 miles per hour
Against the current 30 miles per hour
bv means boat velocity with NO current
cv means current velocity
A) bv + cv = 40 mph
B) bv - cv = 30 mph
Adding both equations:
2bv = 70
boat velocity with NO CURRENT = 35 miles per hour

Using equationA
bv + cv = 40
35 + cv = 40

current velocity = 5 miles per hour

Alchen [17]3 years ago

5 0

Answer:

Speed of current = 5 mph

Step-by-step explanation:

Let u be the speed of boat and v be the speed of current.

A boat makes a 120-mile trip downstream in 3 hours.

120 = 3(u+v)

u + v = 40

It makes the return trip in 4 hours.

120 = 4(u-v)

u - v= 30

Adding both equations

u + v + u - v = 40+30

2u = 70

u = 35 mph

35 + v = 40

v = 5 mph

Speed of current = 5 mph

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the length of a rectangle is five times its width. if the perimeter of the rectangle is 96 ft, find its area.

romanna [79]

Answer:

lets say that the length is L and the width is W. With the given info, we can say that L=5W.

We know that the perimeter is all four sides added, so..

5W*4=20W

20W=96

W=4.8

L= 5*4.8=24

Area is equal to 24*4.8, which is 115.2

Voila! Your answer is 115.2 sq. ft!

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3 years ago

To rent a certain meeting room, a college charges a reservation fee of $15 and an additional fee of $6 per hour. The chemistry c

Dafna1 [17]

Answer:

To spend at most $93, they need to rent the room less than or equal 13 hours.

Step-by-step explanation:

The complete question is

To rent a certain meeting room, a college charges a reservation fee of $15 and an additional fee of $6 per hour. The chemistry club wants to spend at most $93 on renting a room. What are the possible numbers of hours the chemistry club could rent the meeting room? Use t for the number of hours. Write your answer as an inequality solved for t,

Let

t ----> the number of hours

we know that

I this problem the word "at most" means "less than or equal to"

The number of hours rented multiplied by the cost per hour, plus the reservation fee, must be less than or equal to $93

The inequality that represent this situation is

$6t+15\leq 93$

solve for t

subtract 15 both sides

$6t\leq 93-15$

$6t\leq 78$

Divide by 6 both sides

$t\leq 13\ hours$

therefore

To spend at most $93, they need to rent the room less than or equal 13 hours.

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3 years ago

Find the Interest .The loan will be $25,900 over 5years at 6.25%

koban [17]

The interest would be $8,093.75

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2 years ago

Factorize: x² + 3x + 2

zvonat [6]

Step-by-step explanation:

x² + 3x + 2

x² + x + 2x + 2 because 1+2=3 and 2×1=2

By taking out common terms, we get

x(x+1)+2(x+1)

(x+1)(x+2)

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3 years ago

HAVE A NICE DAY WILL GIVE BRAINLST :)

Arturiano [62]

Answer:

DEF = 103

Step-by-step explanation:

brainlyist pls

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3 years ago