WORK AND TIME

One of the most important topics in numerical aptitude is WORK and TIME.

Here are few shortcuts which may help you in solving the problems within fraction of seconds.

1) 'A' does a work in 6 days and 'B' does the same work in 4 days. In how many days work will be completed if they work together.

• whenever you find this 'together' kind of problems first calculate the L.C.M of the given numbers i.e the LCM of 6 and 4 which is 12(It will be the numerator)

                                                          

                      RESULT=                                  L.C.M

                                             ___________________________________
                                        (no of times '6' is              +   (no of times '4' is getting
                                     getting multiplied by LCM)            multiplied by LCM)


                                   =              12/ (2+3)
                                   =              12/5 days

2) 'A' does a work in 20 days and 'B' does the same work in 30 days. Find out in how many days will they complete the work if worked together.

           As seen in the above problem

                    RESULT =            60/(3+2)                   [ since LCM=60 and 20 is multiplied by 3 and
                                                                                                  30 is multiplied by 2]
                                   =            60/5 = 12 days