Answer:
C
Step-by-step explanation:
A geometric series will only converge if - 1 < r < 1
sum to infinity =
The nth term formula for a geometric series is
= a
where a is the first term and r the common ratio
The only summation with - 1 < r < 1 is C where r = - 0.2
Answer:
Weight=2.835
Step-by-step explanation:
See the attached picture for explanation.
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.