From the definition of conditional probability,
and by the law of total probability,
In other words, each cell in the grid left of and above the total column and row represents the joint probabilities (e.g.
). So,
X represents the amount of materials she buys.
A I hope this helps <3333333333333333
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Answer:
a = 12 years
Step-by-step explanation:
Mark is 6 years older than his brother Sam. Now, we are asked to represent Sam’s age by a. This means that if Sam is a years old, Mark is (a + 6) years old.
The sum of their ages is 30, this means that when we add their ages together, we get the sum of thirty.
Mathematically this means a + a + 6 = 30
2a + 6 = 30
This is the equation needed to get a. To get a , we proceed to solve the equation to completion.
2a = 30 - 6
2a = 24
a = 24/2
a = 12
