Respuesta :
Answer:
Step-by-step explanation:
Each hour, Jim does 1/3 of the job if working alone.
Each hour, John does 1/5 of the job if working alone.
Let x = number of hours to do the job if they work together. So, each hour, they do 1/x of the job when they work together.
We get the equation: 1/3 + 1/5 = 1/x
Multiply the equation by the LCD, 15x: 5x + 3x = 15
8x = 15
x = 15/8 = 1 7/8 hrs
ANSWER: (C).