Answer:
B.
[tex] \tt{} \frac{x}{40} + \frac{x}{60} = 1[/tex]
LCD is 120. Multiply all the terms by the LCD.
[tex] \tt{}120 \bigg( \frac{x}{40} + \frac{x}{60} = 1\bigg)[/tex]
[tex] \tt{} \frac{120x}{40} + \frac{120x}{60} = 120[/tex]
[tex] \tt{}3x + 2x = 120[/tex]
[tex] \tt{}5x = 120[/tex]
[tex] \tt{}x = \frac{120}{5} [/tex]
[tex] \huge\boxed{ \tt{}x = 24 \: minutes} [/tex]
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C.
[tex] \tt{} \frac{x}{5} + \frac{x}{6} = 1[/tex]
LCD is 30. Multiply all the terms by the LCD.
[tex] \tt{}30 \bigg( \frac{x}{5} + \frac{x}{6} = 1 \bigg)[/tex]
[tex] \tt{} \frac{30x}{5} + \frac{30x}{6} = 30[/tex]
[tex] \tt{}6x + 5x = 30[/tex]
[tex] \tt{}11x = 30[/tex]
[tex] \tt{}x = \frac{30}{11} [/tex]
[tex] \tt{}x = 2.72727272727[/tex]
[tex] \huge \boxed{ \tt{}x = 3 \: hours} \\ \\ \\ \\ [/tex]
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