Explanation:

Solution :
2M = 22=——- 1 (1 day work—total work =22)
4W = 22———1
6B = 22———-1
2M = 1 work => 1 M = 1/2 work
1 W = 1/4 work
1B = 1/6 work
1 M + 1W +1B = 1/2+1/4+1/6 = 11/12 work
days required = 22/(11/12) = 24 days