Mathematics & Tissue Selling

I would buy tissue at interchanges & MRT station when the disabled peddles them.

This was wat I mean to post all along but it remained elusive to my mind till now.

HQ, LJ & YT were having lunch on the day of the Bintan trip. An uncle came along to sell tissue paper & said "3 for $1. $2 for 5."

Needless to say, HQ onli bought 3 packets.