Three different types of materials X, Y and Z were used in the experiment shown below here. In both
circuits, the bulbs lighted up.
Another different circuit was set up and three of the
materials were placed at three different positions, Q1,
Q2 and Q3.
Based on the above circuits, which one of the following
is wrong?
Positions in the circuit--- Light bulbs
| Q1 | Q2 | Q3 | B1 | B2 | B3 | |
| A | X | Y | Z | No | Yes | No |
| B | Y | Z | X | Yes | Yes | No |
| C | Z | X | Y | Yes | No | Yes |
| D | X | Z | Y | No | No | No |
not understanding
