Answer: a) 
Step-by-step explanation:
Given : For safety reasons, four different alarm systems were installed in the vault containing the safety deposit boxes at a Beverly Hills bank.
Each of the four systems detects theft with a probability of .99 independently of the others .
Probability for independent events
occurs together =
.
Then, the probability that when a theft occurs, all four systems will detect it
= (0.99) x (0.99) x (0.99) x (0.99)

Hence, the probability that when a theft occurs, all four systems will detect it is
.
Hence, the correct answer is a)
.
The window has a shape of a semi-circle (half of a circle).
We know the diameter d = 12 ft.
The area of a (complete) circle is given by the formula:
A = π × r²
The radius can be found by halving the diameter:
r = d ÷ 2
= 12 ÷ 2
= 6 ft
Therefore the area of the circle will be:
<span>A = π × r²
= 3.14 × 6</span>²
= <span>3.14 × 36
= 113.04 ft²
And the area of the semi-circle:
A = </span><span>113.04 </span>÷ 2
= 56.52 ft²
Hence, the area of the window will be 56.52 ft².
+ 19 on both sides, -19 becomes 0, 1 becomes 20 x=20
Answer:
10
Step-by-step explanation:
3 x 3 + 5 - 6 + 2=
PEMDAS states we do multiplication first.
9 + 5 - 6 + 2
Since it's just addition and subtraction, we calculate left to right
14 - 6 + 2
8 + 2
10
920 cm squared. Divide S by 2 then multiply to find the value of T. If S = 368 then T = 552, 368 + 552 = 920.