arithmetic - pallavi can complete a work in 12 days working 8 hours a day sushma can complete the same work in 8 days working 10 hours a day if both pallavi and sushma work together working 8 hours a day in how many days can they complete the work - skillgun

Let P = Pallavi, Q = Sushma.
P can complete the work in (12x 8) hrs = 96 hrs.
Q can complete the work in (8x 10) hrs = 80 hrs.
P's 1 hour's work = 1/96
Q's 1 hrs work = 1/80
(P+Q)'s 1 hour's work = (1/96+1/80)
= 11/480.
So, both P and Q will finish the work in =(480/11) hrs.
Number of days of 8 hours each =(480/11x1/8) hrs.
= 60/11 days
=5x5/11 days.