## To find out how long it will take for all three men to paint the fence, we can use the formula:

time = 1 / (1/8 + 1/7 + 1/5).

To simplify, we can find a common denominator for the fractions 1/8, 1/7, and 1/5. The common denominator is 280.

So, we can rewrite the equation as:

time = 1 / (35/280 + 40/280 + 56/280).

Now, we can add the fractions together and simplify:

time = 1 / (131/280).

To divide by a fraction, we can multiply by its reciprocal:

time = 1 * (280/131).

This gives us the time it will take for all three men to paint the fence, which is approximately 2.1374 hours.