Question

Hannah can paint a room in 9 hours. Destiny can paint the same room in 15 hours. How long does it take for both Hannah and Destiny to paint the room it they are working together.

Answer 1

Not 9+15 lol.

Answer 2

no, it would be a reduced time

Answer 3

I am thinking its 6, but thats wrong

Answer 4

Here it is

how much of the room can hannah paint in 1 hour? 1/20
how much of the room can destiny paint in 1 hour? 1/16

how much of the room can they paint working together in 1 hour?
1/20 + 1/16 =
1/20(4/4) + 1/16(5/5) =
4/80 + 5/80 =
9/80

all of the other work rates were the reciprocal of the hours needed for the full job. Same with this one. So hours for the full job would be 80/9, or 8.9 hours to complete the job together.

1/(hours for 1st person) + 1(hours for 2nd person) = 1/(hours together)

Answer 5

I might've messed up with that, lemme seee

Answer 6

you type really quick!!!!!!

Answer 7

ok, but i got a decimal, which doesnt seem right

Answer 8

Do I..?

Answer 9

yes o.o

Answer 10

Not too quick xD

Answer 11

9/2= 4.5
15/2= 7.5
4.5+7.5=12

12 Hours

Answer 12

So 12 is the answer

Answer 13

no :(

Answer 14

yes, you are probably right..but no, didnt take it

Answer 15

?? Whatcha mean?

Answer 16

Im sure the answer is 12 >.>

Answer 17

its an online homework page, it didnt work :p

Answer 18

ahgahga

Answer 19

It's supposed to be reduced since it's 2 people which make it less time .

Answer 20

Mhmm .-.