Maligayang pagdating sa Imhr.ca, kung saan ang iyong mga tanong ay masasagot ng mga eksperto at may karanasang miyembro. Kumonekta sa isang komunidad ng mga eksperto na handang tumulong sa iyo na makahanap ng mga solusyon sa iyong mga tanong nang mabilis at eksakto. Maranasan ang kadalian ng paghahanap ng eksaktong sagot sa iyong mga tanong mula sa isang malawak na komunidad ng mga eksperto.

A girl, A, took 5 hours to paint a wall. Her friend, B, took twice as much time as A to paint a wall of the same dimensions. How long would the task have taken the girls if they had worked together?

Sagot :

Number of hours to finish the task if the friends worked together: x
Number of hours for Friend A to finish the task: 5
Number of hours for Friend B to finish the task:  2(5) = 10

Equation for Combined Work (task):
1/5 + 1/10 = 1/x

LCM (Least Common Multiple): 10x

Multiply each term by 10x, then simplify:
(10x)(1/5) + (10x)(1/10) = (10x)(1/x)
2x + x = 10
3x = 10
3x/3 = 10/3
x = 10/3   or  3 ¹/₃ hours

ANSWER: It would take 3 ¹/₃ hours for the two friends to finish the task of painting the wall of the same dimensions.