Answer:
(3 x 6) + (2 x 12) + (20 x 18)
Step-by-step explanation:
Number of cartons containing 6 eggs 
Number of cartons containing 12 eggs 
Number of cartons containing 18 eggs 
So,
expression that represents the problem is given by
Number of cartons containing 6 eggs + Number of cartons containing 12 eggs + Number of cartons containing 18 eggs = (3 x 6) + (2 x 12) + (20 x 18)