Question

Andrea can clean a house 4 times as fast as Denise. When they work together, Andrea and Denise can clean a large house in 8 hours. How many hours would it take Denise to clean the house by herself?

20

15

10

5

Answer 1

8*4

Answer 2

8*4/2

Answer 3

16?

Answer 4

B

Answer 5

15? Howd you get that

Answer 6

hmm i really domnt know if Andrea can clean a house 4 times as fast as Denise. right and they both do it 8 hours then e.e

Answer 7

yah that's why its so confusing :P

Answer 8

well lets say that denise did like 2 hours and andrea did 4 times

Answer 9

yah

Answer 10

I think its C

Answer 11

ok @IMStuck do you have anything or no

Answer 12

I'm working on it right now. Give me just a minute or two. Please.

Answer 13

ok great thanks :)

Answer 14

20

Answer 15

how

Answer 16

\[8*\frac{ 5 }{ 2 }\]

Answer 17

oh ok I guess

Answer 18

1+4=5/2 x8

Answer 19

oh ok

Answer 20

is it helped

Answer 21

GOT IT!!!!!

Answer 22

what is it?

Answer 23

Ok, if Andrea cleans in 1/4 of the time, and it takes denise, say, one hour to clean a house, it would take Andrea 1/4 of an hour, right? So Denise could get 1/8 of the house done in 1/x and Andrea could get 1/8 the house done in 1/4 of 1/x. Here's your set up\[\frac{ 1 }{ x }+\frac{ 1 }{ 4 }(\frac{ 1 }{ x })=\frac{ 1 }{ 8 }\]Doing all that math and finding the common denominator of 8x, you get 10 = x. That's the number of hours it takes Denise to clean the house by herself.

Answer 24

omg thank you so much so 10 hours

Answer 25

Yes, 10 hours. So sorry it took so long!

Answer 26

Refer to the attached where Mathematica is used for the final calculation.

Answer 27

no problem thanks for helping me in the first place