Maria can weed 1,000 m² of cogonal farm surface in 40 hours, while her brother, Bryant, can do the same amount of work in 20 hours. If they work together, how long will it take them to weed one hectare (10,000 m2) of cogonal land surface?
As she takes 40 hours to do the entire job (weed 1,000 m²), Maria's per hour rate =
As the brother takes 20 hours to do the entire job (weed 1,000 m²), the brother's per hour rate =
With time that it takes both to do 1 job (1,000 m²) being T, we get:
T + 2T = 40 ------ Multiplying by LCD, 40T
3T = 40
Time taken by both to do 1 job (1,000 m²), or
Time taken by both to do 10 SUCH jobs (weed 10,000 m²) =