The grouping technique is often tested in PSLE Maths. It involves grouping with total value or grouping with difference in value. For this PSLE Question, we adopt the following steps.

Step #1 : Group together 10+2 eggs into one set

Step #2 : Using the total eggs, find the number of sets. 120 / 12 = 10 sets

Step #3 : In 10 sets, there will be 10 x 2 = 20 free eggs

Step #4 : Note that because of the free eggs, there is a saving of $4.80

Step #5 : 20 eggs -> $4.80

10 eggs -> $4.80 / 2 = $2.40 [Ans.]