Question

Michelle and her sister want to bake a cake. it takes michelle 3 hours and her sister 5 hours. how long will it take if they work together?

Answer 1

1/3 + 1/5 = 1/x?

Answer 2

that's all I know tbh XD I'm not sure what to do from here

Answer 3

Working together formula
\[\frac{M \times S}{M + S} = t\]

Hours Michelle can bake a cake alone
Hours her sister can bake a cake alone
t = hours it take if they work together

\[\frac{(3)(5)}{3 + 5} = t\]
\[\frac{15}{8} = t\]
\[\frac{8 + 7}{8} = t\]
\[\frac{8}{8} + \frac{7}{8} = t\]
\[1 + \frac{7}{8} = t\]

So if they work together, it will take 1 and 7/8 hours

@whalexnuker

Answer 4

thanks but this is old :O i got it solved already!

Answer 5

So approximately

1 hour and 53 minutes to bake a cake if both Michelle and her sister work together :)

Answer 6

Yes, but I have given you a shortcut formula