To simplify the expression, we can start by canceling out the common factors in the numerator and denominator of each fraction:

(1 - 1/2) = 1/2
(1 - 1/3) = 2/3
(1 - 1/4) = 3/4
(1 - 1/5) = 4/5

Continuing this pattern, we can see that:

(1 - 1/2)(1 - 1/3)(1 - 1/4)(1 - 1/5) = (1/2)(2/3)(3/4)(4/5)

Now, we can cancel out common factors:

(1/2)(2/3)(3/4)(4/5) = (1/5)

Therefore, (1 - 1/2)(1 - 1/3)(1 - 1/4)(1 - 1/5)...(1 - 1/50) = 1/5.