Pipes A and B are fitted to a tank. A is a filling pipe, and B can be used for either filling or emptying at the same rate. When B is used for filling, it takes time 't' along with A to fill the tank. If B is used for emptying while A is filling the tank, the time taken for the tank to fill up is '5t'. Find the ratio of the efficiency rate of A to that of B.

Three taps A, B, and C can fill an empty tank in 30 minutes, 20 minutes, and 10 minutes respectively. When the tank is empty, all three taps are opened. Taps A, B, and C release chemical solutions P, Q, and R respectively. What is the proportion of solution R in the tank after 3 minutes?

Two inlet pipes J and T can fill a tank in 120 minutes and 144 minutes respectively. If an outlet pipe Z is opened along with them, all three pipes together fill the tank in 240 minutes. How long will pipe Z alone take to empty the full tank?