"Working 8 hours a day, 12 men can do a work in 30 days. Working 4 hours a day,
Channel: Doubtnut
Date: 05/04/2020

"Working 8 hours a day, 12 men can do a work in 30
 days. Working 4 hours a day, 18 men can do the work in 
`30\ d a y s`
b. `40\ d a y s`
c. `45\ d a y s`
d. `50\ d a y s`"