Answer:
0.0975 or 9.75%
Step-by-step explanation:
Assuming that no engines fail simultaneously, the probability that exactly one engine fails is the probability that the first engine fails (15%) multiplied by the probability that the second engine does not fail (100% - 35%):

The probability of exactly one engine failure is 0.0975 or 9.75%
If you roll a six sided dice once, each outcome has a 1/6 probability.
This means 4 has a 1/6 probability.
If you roll a dice 1200 times....
1200 × 1/6 = 1200/6 = 200
You would expect to get a 4 200 times.
Xy = 6
x + y = 9
x + y = 9
x - x + y = -x + 9
y = -x + 9
xy = 6
x(-x + 9) = 6
x(-x) + x(9) = 6
-x² + 9x = 6
-x² + 9x - 6 = 0
-1(x²) - 1(-9x) - 1(6) = 0
-1(x² - 9x + 6) = 0
-1 -1
x² - 9x + 6 = 0
x = -(-9) ± √((-9)² - 4(1)(6))
2(1)
x = 9 ± √(81 - 24)
2
x = 9 ± √(57)
2
x = 4.5 ± 0.5√(57)
x + y = 9
4.5 ± 0.5√(57) + y = 9
- (4.5 ± 0.5√(57)) - (4.5 ± 0.5√(57))
y = 4.5 ± 0.5√(57)
(x, y) = (4.5 ± 0.5√(57), 4.5 ± 0.5√(57))
The two numbers that multiply to 6 and add up to 9 are 4.5 ± 0.5√(57).
Answer:
add up all the sides!!
6+3+3+3+5+12+4+6=38
so the perimeter is 38 ft