See the attached picture to better understand the problem
we know that
in rectangle ABCD
AB=CD
and
AD=BC
therefore
the triangle ACD and triangle ABC are congruent
so
BD=AC
BD=8 units
the answer part a) isBD= 8 unitsPart b) Find angle CBD
we know that
∠ABD+∠CBD=90°---------> by complementary angles
so
∠CBD=90-∠ABD-----> 90-67----> 23°
∠CBD=23°
the answer Part b) is∠CBD=23 degrees
Since she has seven key the probability that the first one will open the door is

if it takes three attempts to open the door,the probability is

if the three attempts would not work
then the probability that the fourth attempt will open the door is

hope this helps
41.8 rounded to the nearest tenth
I’m pretty sure this is right: