The following table gives the values of refractive indices of a few media:

S.No.	$1$	$2$	$3$	$4$	$5$
Medium	Water	Crown glass	Rock salt	Ruby	Diamond
Refractive index	$1.33$	$1.52$	$1.54$	$1.71$	$2.42$

Use this table to give an example of (i) a medium pair so that light speeds up when it goes from one of these media to another (ii) a medium pair so that light slows down when it goes from one of these media to another.