Easiest way:
Look at A and C. To get from A to C you need 6 steps to the right and 2 steps upwards.
Slope means (in layman's terms) that how many steps you take upwards when you take 1 step to the right.
In your case you take 2/6 steps, because it would take you 6 steps to the right to go 2 steps upwards.
A slope of 4 would mean that 1 step to the right is followed by 4 steps upwards. A slope of -5 means 1 step to the right, 5 steps downwards.
To get from A to E you need 9 steps to the right and 3 steps upwards. This means a 3/9 slope. The simplest form of it is 1/3.
1/3 slope means that for every 3 steps to the right you take 1 step upwards.
I hope this was understandable, this is how they taught me this in 5th grade more than a decade ago.
Answer:
Step-by-step explanation:
Given that a machine produces defective parts with three different probabilities depending on its state of repair.
condition Good order Wearing down Needs main Total
Prob 0.8 0.1 0.1 1
Defective 0.02 0.1 0.3
Joint prob 0.016 0.01 0.03 0.056
a) 0.016
b) total = 0.056
c) If not defective from needs maintenance
Prob for not defective = 
From machine that needs maintenance = 0.07
So reqd prob = 