Answer:
a)
b)
c)
Step-by-step explanation:
a)
Rolling a number greater than 3 means you can roll a 4, 5, or 6, which contains rolling a 6. So, the probability is
b)
Rolling a number less than 5 means you can roll a 1, 2, 3, or 4, but because you could also roll an even number, so you could also roll a 6.
So, the probability is
c)
Rolling a 4 or an odd number means you can roll a 1, 3, 5, or 4. So, the probability is
Answer:
First brand of antifreeze: 21 gallons
Second brand of antifreeze: 9 gallons
Step-by-step explanation:
Let's call A the amount of first brand of antifreeze. 20% pure antifreeze
Let's call B the amount of second brand of antifreeze. 70% pure antifreeze
The resulting mixture should have 35% pure antifreeze, and 30 gallons.
Then we know that the total amount of mixture will be:
Then the total amount of pure antifreeze in the mixture will be:
Then we have two equations and two unknowns so we solve the system of equations. Multiply the first equation by -0.7 and add it to the second equation:
+
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We substitute the value of A into one of the two equations and solve for B.