Question

It takes you 45 minutes to clean the fish tank and it takes your sister 30 minutes. how long does it take the two of you working together to clean the fish tank

Answer 1

It takes you 45 minutes to clean the fish tank and it takes your sister 30 minutes. how long does it take the two of you working together to clean the fish tank

Answer:

My 1 minute work =$\frac{1}{45}$

My sisters 1 minute work =$\frac{1}{30}$

My and My sister's 1 minute work =$\frac{1}{45}+\frac{1}{30}$

                                                        =$\frac{5}{90}$

                                                        =$\frac{1}{18}$

$\therefore$ Me and My sister will finish the work in $\frac{18}{1} =18$ minutes