Question

a ,b and c together can do a piece of work in 15 days b alone can do it in 30. days and c alone can do in 40 days in how many days will a alone do the work

Answer 1

A, B and C together can do a piece of work = 15 days
one day work of A,B and C                           = 1/15
B alone can do a piece of work                     = 30 days
one day work of B                                          = 1/30
C alone can do a piece of work                     =  40 days
one day work of C                                          =  1/40
one day work of A                                          =  [1/15-(1/30+1/40)]
                                                                       =  1/120
A alone can do a piece of work                      =  120 days

Answer 2

Step-by-step explanation:

I hope you will understand my handwriting.

Please mark me as brainlist..