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?
2007-07-02 06:02:32 · 7 answers · asked by ManiacTripx 1 in Science & Mathematics ➔ Mathematics
In work problems, we can add the portion of each person's work done in one hour. Relation: work done = time * rate of work.
Thus together, in one hour, they can do: 1/4 + 1/6 = 5/12.
Thus the whole house can be finished in 12/5 hours.
d:
2007-07-02 06:08:36 · answer #1 · answered by Alam Ko Iyan 7 · 0⤊ 1⤋
Sally can paint 1/4 of a house each hour
John can paint 1/6 of a house each hour
X is hours together painting:
X(1/4 + 1/6) = 1 house painted
X (3/12 + 2/12) = 1
X(5/12) = 1
X = 1/ (5/12) = 1* (12/5) = 2.4 hours = 2 hours 24 minutes
2007-07-02 06:06:56 · answer #2 · answered by MamaMia © 7 · 1⤊ 2⤋
Sally can paint 1/4 of a house per hour and John can paint 1/6 of a house per hour, so working together they can paint 1/4+1/6=5/12 of a house per hour, so to paint one house will take them 12/5 hours, or 2.4 hours.
2007-07-02 06:08:37 · answer #3 · answered by Anonymous · 0⤊ 2⤋
1/4x + 1/6x = 1
12(1/4x) + 12(1/6x) = 12(1)
3x + 2x = 12
5x = 12
5x / 5 = 12 / 5
x = 12/ 5
x = 2 2/5
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To solve for the minutes. Multlip.ly 2/5 times 60
2/5(60) =
120/5 =
24
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Sally and John working together can paint the house in 2 Hours and 24 minutes
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2007-07-02 06:17:08 · answer #4 · answered by SAMUEL D 7 · 3⤊ 0⤋
the rate to paint a house for
Sally = 1/4 house/hr
John = 1/6 house/hr
so, together per hour they can paint: 1/4 + 1/6 =5/12 house/hr
to paint the entire house, it will take both of them
1 house / (5/12) house/hr = 12/5 hr = 2 hr 24 min
2007-07-02 09:02:38 · answer #5 · answered by buoisang 4 · 1⤊ 1⤋
2 hours 24 minutes
2007-07-02 06:07:57 · answer #6 · answered by deflagrated 4 · 0⤊ 1⤋
a million. locate the least elementary element, if a probability (no). multiply the 1st & 2d variables (4 hundred). locate 2 numbers that provide you 4 hundred while greater & - 40(midsection) while extra/subtracted (-20 & -20). 16x² - 20x - 20x + 25 => combine "like" words & element. (16x² - 20x) - (20x + 25) => locate the least elementary factors. 4x(4x - 5) - 5(4x - 5) (4x - 5)(4x - 5) (4x - 5)²
2016-11-07 23:05:31 · answer #7 · answered by ? 4 · 0⤊ 0⤋