1st problem:
A = 630 cm
2nd problem:
A = 104 cm
All I can see on the picture you provided.
Center of the door
26 1/3 divided by 2
change to an improper fraction
(3*26+1)/3 =79/3
79/3 divided by 2
copy dot flip
79/3 * 1/2
79/6
change to a mixed number
13 1/6
10 1/4 divided by 2
change to an improper fraction (4*10+1)/2 = 41/4
41/4 divided by 2
copy dot flip
41/4 * 1/2 =41/8
change to a mixed number
5 1/8
the left of the bar should be 5 1/8 from the center
to find how far from the left side to place the bar
13 1/6 - 5 1/8 =
get a common denominator
13 4/24 - 5 3/24= 8 1/24 inches
Answer: place the bar 8 1/24 inches from each edge
The final probability is the weighted average of the playing probabilities calculated over the possible weather options:
P(john practices cello; given that it rains) * P(it rains) +
P(john practices cello; given that it does not rain) * P(it does not rain) =
0.6 * 0.7 + 0.4 * 0.3 = 0.54
The probability is 54%