Water if flowing from 2 different sinks, one is 30 degree the other is 100 degree, the 30 degree one fills the tank in 3 minuites, while the 100 degree one fills it in 7 minuites.
I know I have to apply the proportions to get the average temperature but I don't know exactly how. The proportion is 100 degree water (3:7) 30 degree water. I tried these ways: (100*0.3 + 30*0.7)/2 , but i'm not sure if that's right.