Answer:
4 4/9 days.
Step-by-step explanation:
You work in rates per day, so:
1/10 + 1/8 = 1/x where x is the number of days working together.
Multiply through by the LCD 40x:
4x + 5x = 40
9x = 40
x = 40/9 = 4 4/9 days.
Answer: 40/9 days
Step-by-step explanation: let x be the time when they work together
daily rate of the first programmer = 1/10
daily rate of the second programmer = 1/8
daily rate when they work together = 1/x
Therefore:
1/10 + 1/8 = 1/x
solving the equation:
9/40 = 1/x
x = 40/9