Question

Lance can paint the room 5 hours, while Kim can paint the same room in 4 hours. How many hours would it take for them to paint the room together?

9
20
twenty ninths
nine twentieths

Answer 1

twenty ninths

Answer 2

find out what farction of the room they can paint in 1 hour in terms of time

Answer 3

nine twentieths. you just add them and then turn it into a number

Answer 4

lance paints 1/5 of room in 1 hour, Kim paints 1/4
Working together they paint 1 / t

so
1/5 + 1/4 = 1/t

solve for t

Answer 5

I wish people wouldn't just give the answer

Answer 6

yea i get 9/20.. thank you.

Answer 7

its not 9/20
its 20 / 9

multiply each fraction by the LCM 20t, we get
4t + 5t = 20
t = 20/9

Answer 8

http://www.wolframalpha.com/input/?i=1%2F5+%2B+1%2F4+%3D+1%2Ft

Answer 9

? o-o

Answer 10

OHHHHHh i seeee ok... nvm.

Answer 11

lol

Answer 12

lol cx thanks.

Answer 13

yw