23. 2/3= 0.66 repeating Answer: 98.66 repeating
25. 26.2 = 26 and 2/10 Answer: 26 and 2/10 or 262/10
D is a function because there are no repeated x values
for example b is not a function because we have (0,-7) and (0,-9)
The probability any one system works is 0.99
So the probability of any one system failing is 1-0.99 = 0.01, so basically a 1% chance of failure for any one system
Multiply out the value 0.01 with itself four times
0.01*0.01*0.01*0.01 = 0.000 000 01
I'm using spaces to make the number more readable
So the probability of all four systems failing is 0.00000001
Subtract this value from 1 to get
1 - 0.00000001 = 0.99999999
The answer is 0.99999999 which is what we'd expect. The probability of at least one of the systems working is very very close to 1 (aka 100%)
#4(a)
row-seat: 3- 13, 4-15, 5-17, 6-19, 7-21
(b)
the equation works for row 1 but not for any of the rows after this
Ex: Row 2, S=7(2)+2, this would equal 14 but there isn't 14 seats in row #2
(c)
S=2(1)+7, there is 9 seats in row 1
2(2)+7=11, there is 11 seats in row 2
2(3)+7= 13, there is 13 seats in row 3
(d)
2(15)+7=37
2*15=30, 30+7=37
(e)
91=2(r)+7
91-7=2(r)+7-7
84=2(r)
84/2=2(r)/2
42=r, the row with 91 seats is row 42