I need help with number 13

21 Tables

52 Chairs

Combination of both: Sander can complete 15 sets of chair/table, Lather can complete 22 sets of chair/table.

Step-by-step explanation:

Lathe operator works 6 hrs/day or 360 minutes

Chairs: 360/8 = 45 ; Tables: 360/8= 45

Sander works 7 hrs/day or 420 minutes

Chairs: 420/8= 52.5= 52 ; Tables: 420/20= 21

or,

For the Lathe operator to complete one set of chair and table = 16 minutes

360/16 = 22.5= 22 sets

For the Sander to complete one set of chair and table = 28 minutes

420/28 = 15 sets.