Question

hello every body
could any one explain for me this question included in the picture

Answer 1

i try to solve it like this:
(0.07 + 0.14) - (0.07 * 0.14) = 0.2002
1-0.2002 = 0.7998

0.05*0.03 = 0.0015
1-0.0015 = 0.9985

0.7998 * 0.9985 = 0.7986

Answer 2

i don't think this answer is correct
could any one help me please?

Answer 3

for the system to 'function' you need a working path from start to finish.

You have three 'serial' features, but 1 of them is a 'parallel' option

Parallel means 'OR' (because either one OR the other can be functional and you will still have a path)

Serial means 'AND' (because ALL sections must function for a path to exist)

SO
Write a logical statement like

A OR B AND (C OR D) (I said 'like' this - this is not correct)

You can then work out the probability of that statement from the individual propabilities.

Answer 4

thank you but could you please give me steps
i found the last answer from a book, but i don't know how to get this answer.

the answer is 0.9125

Answer 5

still i cannot understand

Answer 6

how can i get 0.9125

Answer 7

help help help

Answer 8

you can draw up a table of possible outcomes:

abcd
-----
ssss

sssf
ssfs
sfss
fsss

ssff
sfsf
fssf
sffs
fsfs
ffss

fffs
ffsf
fsff
sfff

ffff

------------------------------
now: if a or b fails, the whole thing fails; if both c and d fail, the whole thing fails

ssss

sssf
ssfs
sfss = f
fsss = f

ssff = f
sfsf = f
fssf = f
sffs = f
fsfs = f
ffss = f

fffs = f
ffsf = f
fsff = f
sfff = f

ffff = f

-----------------------------

this leaves us with 3 cases in which it succeeds:

ssss
sssf
ssfs

add up the probabilities of those cases ....

Answer 9

As = .95; Bs = .97
Cs = .93; Cf = .07
Ds = .86 ; Df = .14

.95*.97*.93*.86
+ .95*.97*.93*.14
+ .95*.97*.07*.86
----------------
.9125


http://www.wolframalpha.com/input/?i=++++.95*.97*.93*.86+%2B+.95*.97*.93*.14+%2B+.95*.97*.07*.86