In which of the logic gate the following statement is true? "The output is high when either of the inputs is high but not if both inputs are high"

The output of an $OR$ gate is connected to both the inputs of a $NAND$ gate. The combination will serve as a

For the given logic circuit,what should be the value of input $ABC$ to get an output $Y = 1$?

In the digital circuit shown in the figure,for the given inputs,the $P$ and $Q$ values are:

$A$ building has two overhead water tanks, each fitted with a sensor $(S_1, S_2)$ which goes to $0$ when the water level in the tank falls below a set value and remains $1$ otherwise. $A$ common pump is used to raise water from an underground storage tank to these overhead tanks. Of the following circuits, which one will turn on $(P = 1)$ the pump only when at least one of the tanks has a water level below the set value?

What is the truth table for the given logic gate combination?