Jokuc

you lost me at "Add. 8 + 10 = 18"

..why? hah

Because you've got 8/80 and 10/80, and what you're doing is adding the amount of time it takes for both of those faucets to fill up the bathtub. By adding them, you get 18/80, which would be the speed of the two faucets running together. c:

no nvm

but someone in my class said the answer is 4 min 27 secs :L