Math 141, Sem. I, 1998-99 (R.A. Brualdi)
Handout 10 (October 9, 1998)
Topic: Quiz # 3 (10 points per problem)
1. You have a container consisting of 10 quarts of an sugar-water
solution which is 25% sugar.
(a)How much pure sugar must you add to get a solution which is
40% sugar?
(b) Suppose you could extract pure water from the given
sugar-water solution. How much must you extract in order to have a
mixture which is 40% sugar?
[Answers correct to two decimal places.]
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Scratch work - I will not read this.
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Polished solution:
2) The towns A and C are 20 miles apart with town B in between as
shown (not to scale):
A-----------B--------------C
At 8:00 AM one day you start to bike from A to B at 10 mph. At
8:10 AM the same day, your friend bikes from C to B at 12 mph, and
arrives at B five minutes after you do. How far from A and C is B?
Answer is to be correct to two decimal places.
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Scratch work - I will not read this.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Polished solution: