Answer:
a - about 3 packs cause you have to round up
b - $50.76
Step-by-step explanation:
First you divide 42 and 18.
42/18=2.33
You have to round up cause you can't have half of a pack, you can't just buy half of a pack.
So, it is rounded to 3 packs.
Next you have to multiply the number of packs and the cost of each pack of water bottles.
16.92*3=$50.76
a - you have to buy 3 packs
b - the total cost is $50.76