Question

30 people can complete a job in 12 days. How many days will 20 people take for completing the same job?

Answer 1

30 people     x1             12 days    y1

20 people      x2                 ?          y2

no of people and no of days are in inverse proportion 

x1 * y1 = x2*y2

30 *12 = x2 * 20

x 2 = 30 *12 /20

x2 = 18

so 20 people take 18 days to co,mplete the work