Question

A pack of 9 toilet rolls cost £4.23

Answer 1

9pack  9dived into 4.23 =.47 while 4 pack is 4divedinto 1.96 = .49 i would buy the 9 pack hope this helps

Answer 2

For this question you should first find a pack of one toilet roll for each cost so you can say : 
if 9 toilet rolls cost 4.23 so 1 toilet roll is : 4.23/9 = 0.47 
and if 4 toilet rolls cost 1.96 so 1 toilet roll is : 1.96 /4 = 0.49 
so 0.49 is greater than 0.47 so a pack of 9 toilet rolls gives the better value for money :)))
i hope this is helpful 
have a nice day