Answer Happy

A test of weld strength involves loading welded joints until a
fracture occurs. For a
certain type of weld, 60% of the fractures occur in the weld
itself, while the other
40% occur in the beam. A number of welds are tested. Let X be the
number of
tests up to and including the first test that results in a weld
itself. where X
represents the number of tests up to and including the second weld
fracture.
What is the distribution of X? and write its expression including
the values.