Answer: (d) 50%
Explanation:
Total hours invested per day = 20
Boxes produced in a day = 400 boxes
(a) Productivity per day (Old) = 20 boxes per hour
(b) Suppose they can increase the rate to 600 boxes per day, then,
New productivity per day = 30 boxes per hour
(c) Unit increase in productivity = 10 boxes per hour
(d) [tex]Percentage\ increase\ in\ productivity=\frac{New\ productivity-old\ productivity}{old\ productivity}\times100[/tex]
[tex]Percentage\ increase\ in\ productivity=\frac{30-20}{20}\times100[/tex]
= 50%