2. Tap A fill tank in 6mins, Tap B fill in 9mins. Pipe C empty the tank in 15mins, what is the time taken to fill up the tank when the 2 taps and pipe are in the tank ?

Question

anonymous · Answer

da/dt = 6
db/dt = 9
dc/dt = -15

anonymous · Answer

am i heading in the right direction ?

mathmath333 · Answer

is the answer $4.73~min$ i need to confirm

mathmath333 · Answer

the part filled in 1 min =$\dfrac{1}{9}+\dfrac{1}{6}-\dfrac{1}{15}=\dfrac{19}{90}$

and the time taken to fill it is $\dfrac{90}{19}$

mathmath333 · Answer

so its equal to 4 min 44 sec

anonymous · Answer

please @HatcrewS if you kno chinese could you please help meh there is no one in the chinese subject.