P and Q can complete a work in 36 and 12 days respectively. If they work alternate days starting with P, in how many days P and Q can complete the work alternatively?
1
12 days
2
16 days
3
18 days
4
20 days
5
26 days
P and Q can complete a work in 36 and 12 days respectively. If they work alternate days starting with P, in how many days P and Q can complete the work alternatively?