Question

B will do a work in 4 days and M will do the same work in 12 days. in how many days will the two do it together?

Answer 1

3 days is the answer....

Answer 2

Total no of days B works=4
Total no of days M works=12
One day work of B=1/4
One day work of M=1/12
Total no of days the will work together=1/4+1/12 ( Take LCM ) 
                                                            =(3+1)/12
                                                            =4/12
                                                            =1/3
M and B works together=3 days