o mow a grass field a team of mowers planned to cover 15 hectares a day. After 4 working days they increased the daily productivity by 33×13%33×13%, and finished the work 1 day earlier than it was planned.
A) What is the area of the grass field?
B) How many days did it take to mow the whole field?
C) How many days were scheduled initially for this job?  Options:
A) 387
B) 39
C) 37
D) 20
E) 28

Rationale: hint : see problem 20 and solve by yourself . answer : a ) 120 hectares ; b ) 7 days ; c ) 8 days . answer : d
Answer: D