Respuesta :

Answer:

Step-by-step explanation:

1/3*X +1/4*X = 1

         Use common denomination of 3*4=12

 

          (4X + 3X) / 12  =  1  This implies that 7X/12 = 1.

Solving for X you get X=12/7 = 1.71 hours is the answer.