A can do work in 12 days and B can do in 15 days the together work complete in how many days

60/9

The best way to solve time and work questions is buy considering LCM of the two numbers here u can take 60 as it is divisible by both 12 and 15 If a takes 12 days to complete 60 work it's power is 5 similarly for b 60/15 means it's power is 4 Now when they are working together their total power is 9 and the work to be down is 60 hence the time becomes 60/9