Jack and Serena can write a lab report together in 12 hours. If all people work at the same rate, how many hours would it take to write a lab report if Kay joins Jack and Serena?

P.S.

Any other solution before this is wrong.

Guest Aug 16, 2022

#1**0 **

1/J + 1/S ==1/12

But J == S

1/J + 1/J ==1/12, solve for J

J == 24 hours - time it takes Jack working alone to write the lab report

S == 24 hours - ...................Serena..........................................................

Kay ==24 hours as well:

Therefore: Jack, Serena and Kay would finish the report in:

**3 / 24 ==8 hours**

Guest Aug 16, 2022