If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together?
2006-08-25 22:33:56 · 13 answers · asked by Anonymous in Education & Reference ➔ Homework Help
in 1 hrs' time,
sally can paint ¼ of a house
john can paint 1/6 of a house
in total,
sally and john can paint ¼ + 1/6 = 3/12 + 2/12 = 5/12 of a house in 1 hrs' time
so to paint 5/12 of a house, it takes both of them 1 hour.
therefore to paint 12/12 of a house(the whole house), it will take them:
5/12 house --- 1hr
12/12 house--- 1/(5/12) * 12/12 = 12/5 *12/12 = 12/5 = 2.4hrs
thus it will take both of them 2.4 hrs or 2hrs 24mins to paint the house together.
2006-08-25 23:03:10 · answer #1 · answered by mei mei 4 · 0⤊ 0⤋
the solution is:
= 1/4 + 1/6 (i reciprocated both numbers)
= 3/12 + 2/12 (then i add the two)
= 5/12 (i get this so now i flip it again)
=12/5 or 2 and 2/5 hours (2/5 hours is 24 mins)
= It will take those two lowlives 2 hours and 24 mins to paint the house, or less than ten minutes to call for a house painter, or less than a minute to realize that their house isn't so bad and decide to keep it that way.
2006-08-25 22:50:58 · answer #2 · answered by Big Bird 3 · 0⤊ 0⤋
sigh. how sad the math skills in this country. well, the writing skills too.
X/4 + X/6 = 1 is how you solve this.
Let X = amount of time spent (they will finish at the same time, therefore you can use one variable. in other types of questions, you have modify X by something.)
x/4 = sally
x/6 = jon
If sally paints for 4 hours, then x = 4, and 4/4 = 1. sally can do 1 job in 4 hours.
If jon paints for 6 hours, then x = 6, and 6/6 = 1.
Combining them becomes the formula above.
k, i worked out the answer and nobody has mentioned it yet.
2006-08-25 22:40:27 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Shally can paint one house in 4 hrs
so shally =1/4
john can paint one house in 6 hrs
so john=1/6
shally+john=1/4+1/6
so both of them will take 2hrs and 40 mins
2006-08-25 22:45:40 · answer #4 · answered by Anonymous · 0⤊ 0⤋
4 hours, because Sally will keep B**tching at John to keep up with her and John will be in a crabby mood and he will just walk away and Sally will have to do it all her self.
2006-08-25 22:37:18 · answer #5 · answered by Ken 3 · 1⤊ 0⤋
Not 5 hours.
Less than 3.
2006-08-25 22:36:12 · answer #6 · answered by Joe 2 · 0⤊ 0⤋
It's been a while since I had to use algebra, and...I was never very good at retaining math after the class was over. Even though I got A's in all my math classes. Wow...this is kinda awkward.. :)
2006-08-25 22:39:33 · answer #7 · answered by Trimere 4 · 0⤊ 0⤋
almost in 3 hours
2006-08-25 23:26:08 · answer #8 · answered by Anonymous · 0⤊ 0⤋
2 hours and 45 minutes im pretty sure
2006-08-25 22:36:46 · answer #9 · answered by oxenofterror 2 · 0⤊ 0⤋
definitly less than 4
2006-08-25 23:56:01 · answer #10 · answered by taffylaura 1 · 0⤊ 0⤋