Seven kids Px, Qx, Rx, Sx, Tx, Ux, and Vx are sitting in a row, all facing in the same direction. Vx sits exactly at the center of the row. Only three kids are sitting between Px and Sx. Only Qx is sitting between Sx and Tx. Tx is sitting third to the right of
Vx. Who is sitting at the extreme left end?

 Vx is sitting exactly at the middle and Tx is sitting third to the right of Vx.  Since only Qx is sitting between Sx and Tx, this means Sx must be to the immediate right of Vx.  Only three kids are sitting between Px and Sx. This means Px is at the extreme left and Ux/Rx can interchangeably occupy the remaining two positions. Final arrangement is shown below: From above arrangement, it is clear that ‘Px’ is sitting at the extreme left end. Hence, the correct answer is (D).