The diagram shows a circular horizontal board divided into six equal sectors. The sectors are labelled white (W), yellow (Y) and blue (B). W W W B A pointer is pinned to the centre of the board. The pointer is to be spun and when it stops the colour of the sector on which th pointer stops is recorded. The pointer is equally likely to stop on any of the six sectors. Eva will spin the pointer twice. The following tree diagram shows all the possible outcomes. Eva will spin the pointer twice. The following tree diagram shows all the possible outcomes. First spin Second spin (a) 91 13 Blue Yellow White Find the probability that both spins are yellow. 16 16 Blue Yellow White Blue Yellow White Blue 3 Yellow White