Question

(05.09)

Reggie can line a football field in 120 minutes. Rosalinda can line a football field in 80 minutes. If they work together, how many minutes does it take them to line a football field?

Answer 1

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Answer 2

\[\frac{ x }{ 120 } + \frac{ x }{ 80 } = 1\]

Answer 3

you can use this formula:
\[\frac{ 1 }{ t }=\frac{ 1 }{ a }+\frac{ 1 }{ b }\] in this formula a is the time that first person can do a work. b is the time that second person can do a work. t is the time that if both persons work together can finish it.
\[\frac{ 1 }{ t }=\frac{ 1 }{ 80 }+\frac{ 1 }{ 120 }\]