Question

Maria, an experienced shipping clerk, can fill a certain order in 13 hours. Felipe, a new clerk, needs 15 hours to do

the same job. Working together, how long will it take them to fill the order?

Answer 1

7 hr 10 min 12 seconds

Explanation:

Maria, an experienced shipping clerk, can fill a certain order in 13 hours. Felipe, a new clerk, needs 16 hours to do the same job. Working together, how long will it take them to fill the order?

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Maria rate = 1/13 job/hr

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Felipe rate = 1/16 job/hr

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Together rate = 1/x job/hr

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Equation:

rate + rate = Together rate

1/13 + 1/16 = 1/x

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16x + 13x = 13*16

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29x = 13*16

Answer 2

≈ 7 hours

Explanation:

Maria can do full job in 13 hours,

she can do 1/13 part of job in one hour

Felipe can do full job in 15 hours,

he can do 1/15 part of job in 1 hour

Together they can do:

• 1/13 + 1/15= 28/13*15= 28/195 of job in 1 hour

to complete full job they need:

• 1 ÷ 28/195= 195/28 ≈ 7 hours