Question

pls answer this unitary method question step by step??

Answer 1

STEP 1: Find their rate:

Mason A takes 12 hours

⇒ 1 hour = 1/12 of the work

Mason B takes 9 hours

⇒ 1 hour = 1/9 of the work

Mason C takes 12 hours

⇒ 1 hour = 1/12 of the work

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STEP 2: Find the rate if they worked together:

1 hour = 1/12 + 1/9 + 1/12 = 5/18

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STEP 3: Find number of hours needed

5/8 of the work = 1 hour

1/8 of the work = 1 ÷ 5 = 1/5 hour

8/8 of the work = 1/5 x 8 = 8/5 hour

8/5 hour = 1 hour 36 mins

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Answer: They will need 1 hour 36 mins hour if they worked together.

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STEP 4: Find their ratio:

Ratio of A : B : C = 1/12 : 1/9 : 1/12

Change the denominator to be the same:

Ratio of A : B : C = 19/108 : 12/108 : 19/108

Divide by 108 through:

Ratio of A : B : C = 19 : 12 : 19

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Answer: The ratio of A : B : C = 19 : 12 : 19