If 14 men cultivates 42 acres of land in 18 weeks, how many weeks will 21 men working at the same rate take to cultivate 56 acres of land.?

Answer 1

acres = k(men * time)
given: acres = 42, time = 18, men=14
42 = k(14)(18)
k = 1/6

acres = (1/6)(men)(time)
56 = (1/6)(21)(time)
time = 6*56/21 = 16

or:
14 men cultivate 42 acres of land in 18 weeks
1 man cultivates 42/14 acres of land in 18 weeks
21 men cultivate 42/14*21 acres of land in 18 weeks
21 men cultivate 63 acres of land in 18 weeks
21 men cultivate 1 acre of land in 18/63 week
21 men cultivate 56 acres of land in 18/63*56 weeks
21 men cultivate 56 acres of land in 16 weeks

Answer 2

I didn't understand this formula pls explain the procedure, thanks.