Answer:
2 day
Step-by-step explanation: Before the days start Chad has 8 and Keenan has 0. The next day (day 1) chad sells 1 equalling 9 tubs and Keenan sells 5 equalling 5 tubs. The next day (day2) Chad sells another 1 equalling a total of 10 and Keenan sells another 5 equalling a total of 10 so at the end of day 2 they have both sold 10 tubs