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
Norma-Jean [14]
2 years ago
11

A group of college students is volunteering for Help the Homeless during their spring break. They are putting the finishing touc

hes on a house they built. Working alone, Irina can paint a certain room in 9 hours. Paulo can paint the same room in 8 hours. Write an equation that can be used to find how long it will take them working together to paint the room. How many hours will it take them to paint the room? If necessary, round your answer to the nearest hundredth.
A. \frac{x}{9} + \frac{x}{8} = 1; 2.18 hours
B. \frac{1}{9} + \frac{1}{8} = \frac{1}{x}; 3.73 hours
C. \frac{9}{x} + \frac{8}{x} = 1; 8.5 hours
D. \frac{x}{9} + \frac{x}{8} = 1; 4.24 hours
Mathematics
1 answer:
attashe74 [19]2 years ago
6 0

Answer:

D 4.24

Step-by-step explanation:

Assume the area of room be A

Irina painting speed be x, 8x = A

Paulo painting speed be y, 9y = A

Together painting speed = x + y = A/8 + A/9

Assume together painting time = t

(A/8 + A/9) t = A

(1/8 + 1/9)t = 1

17t = 72

t = 4.24

You might be interested in
The formula for the cost of buying a car is:
Mice21 [21]

Answer:

a) The cost of buying this car is of £6200.

b) The monthly payment is of £450.

Step-by-step explanation:

The cost of buying a car is given by:

cost = 12 X monthly payment + deposit

a) Find the cost of a car when the monthly payment is £350 and the deposit is £2000.

So

cost = 12*350 + 2000 = 4200 + 2000 = 6200

The cost of buying this car is of £6200.

b) The cost of another car is £8000. Find the monthly payment when the deposit is £2600.

Again, the formula is applied. So

cost = 12 X monthly payment + deposit

8000 = 12x + 2600

12x = 5400

x = 5400/12

x = 450

The monthly payment is of £450.

7 0
2 years ago
1) x+30 = 40
soldier1979 [14.2K]

1)x+30=40

x=40-30

Answer :x=10

2)30-20+2x=10

10+2x=10

2x=0

Answer: x=0

3)3x-10+13=-2x+28

3x+3=-2x+28

3x+2x+3=28

3x+2x=28-3

5x=28-3

5x=25

x=5

4)13x-23-45=-7x+12

13x-68=-7x+12

13x+7x-68=12

13x+7x=12+68

20x=12+68

20x=80

x=4

5)2(x+4)=10x+24

2x+8=10x+24

2x-10x+8=24

2x-10x=24-8

-8x=24-8

-8x=16

x=-2

6)3(x-5)=1-(2x-4)

3x-15=1-(2x-4)

3x-15=1-2x+4

3x-15=5-2x

3x+2x-15=5

3x+2x=5+15

5x=5+15

5x=20

x=4

7)5x-10=15

5x=15+10

5x=25

x=5

8)x+4=x+6

4=6

no solution

PLEASE MARK ME AS BRAINLIEST

4 0
3 years ago
True or false: the standard deviation is the square root of the variance.
Vilka [71]
Why not look up "standard deviation" yourself, to be sure?  But yes, the std. dev. is the sqrt of the variance.
6 0
3 years ago
Angle a measured 59 degrees. if angle a is rotated 45 degrees, what is the measurement of angle a’?
sp2606 [1]
HAHA funny. The angle stays the same. 59 degrees.

8 0
3 years ago
Read 2 more answers
A teacher gave her class two exams; 60% of the class passed the second exam, but only 48% of the class passed both exams. What p
zubka84 [21]
I think 80%

I also got stuck on it and searched it up I think its 80% but if I'm wrong I'm sorry 
7 0
3 years ago
Read 2 more answers
Other questions:
  • Pls help! i’m not sure if the answer i chose is the right 1.
    12·1 answer
  • What multiplication problem is equivalent to 3 3/8 divide by 3/8
    9·1 answer
  • HELP PLEASSEEE IMPORTANT QUICK
    11·1 answer
  • Simplify. (√5+4) (√5 - 2)​
    12·2 answers
  • Boat A leaves a dock headed due east at 2:00PM traveling at a speed of 9 mi/hr. At the same time, Boat B leaves the same dock tr
    13·1 answer
  • There is an outbuilding that has an area of 80 square feet. The rectangle on the blueprint that represents the outbuilding has a
    15·1 answer
  • A speaker is in the shape of a cube with an edge length of 3.5 inches. The speaker is sold in a package in the shape of
    14·1 answer
  • Question 3<br> Find the Slope.<br> (2,8) and (4, -3)
    15·2 answers
  • The area of a rectangle is 108.35 in2 and the length is 7.8 in. Find the width.
    12·2 answers
  • 3. I am a cube that has a length,<br> width, and height of 1 unit.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!