Ram alone can do a work in 20 days. Mohan is 25% more efficient than Ram. Ram and Mohan started working and worked for 4 days. If Sita alone completed the remaining job in 22 days. How many days Sita alone takes to complete the entire job?

Ram's efficiency: 1/20 work per day. Mohan is 25% more efficient, so his rate = 1.25×(1/20) = 1/16 per day. In 4 days, Ram and Mohan complete: 4×(1/20 + 1/16) = 4×(4/80 + 5/80) = 4×(9/80) = 9/20 of work. Remaining work = 1 - 9/20 = 11/20. Sita completes 11/20 work in 22 days, so her rate = (11/20)/22 = 11/440 = 1/40 per day. Therefore, Sita alone takes 40 days to complete the entire job.