The amount of nappy pants you get in your case depends on the size of nappy pant you purchase. Please see the below guide that tells you how many nappies you will receive for each size:
Size 5 - 6 packs of 20 Nappy Pants (120 in total)
Size 6 - 6 packs of 18 Nappy Pants (108 in total)
Size 7 - 6 packs of 16 Nappy Pants (96 in total)