Answer:
0.625 = 62.5% probability that part B works for one year, given that part A works for one year.
Step-by-step explanation:
We use the conditional probability formula to solve this question. It is

In which
P(B|A) is the probability of event B happening, given that A happened.
is the probability of both A and B happening.
P(A) is the probability of A happening.
The probability that part A works for one year is 0.8 and the probability that part B works for one year is 0.6.
This means that 
The probability that at least one part works for one year is 0.9.
This means that: 
We also have that:

So


Calculate the probability that part B works for one year, given that part A works for one year.

0.625 = 62.5% probability that part B works for one year, given that part A works for one year.
Answer:
Slope is -12
Step-by-step explanation:
change of y/change of x = -12
Answer:
O.26
Step-by-step explanation:
Divide The cost from the pieces
Answer: Todd used 27 black tiles.
Step-by-step explanation:
Let x represent the number of black tiles that Todd used.
Todd uses 21 white tiles & some black tiles to make a mosaic. This means that the total number of white and black tiles that Todd used is 21 + x
Each tile has an area of 3 square centimeters. This means that the total area covered by the white tiles is
21 × 3 = 63 square centimeters
Also, the total area covered by the black tiles is
3 × x = 3x square centimeters
The mosaic has a total area of 144 square centimeters. This means that
3x + 63 = 144
3x = 144 - 63
3x = 81
x = 81/3 = 27