4) Let the total work = LCM (8, 12, 16) = 48 units Work done by R in one day =(
48
16
)=3units Work done by P and Q in one day =(
48
8
)+(
48
12
)=10units Work done on every second day= 3 + 10 = 13 units Work done in first two days= 3 + 13 = 16 units Average one day work = 8 units ∴ Number of days taken to finish48 units of work = 6