Question 18547: How do you work these two problems. I'm very confused about the questons below:
1.Jessica has 4 times as many books as John and five times as many as Karen. If Karen has more than 40 books what is the least number of books jessica could have? Is it:
(a)240 (b)220 (c) 210 (d)205 (e)200
Here's the second one:
Judy is now twice as old as Adam but 6 years ago she was 5 times his as old as he was. How old is Judy now? Is it:
(a)10 (b)16 (c)20 (d)24 (e)32
Answer by Alwayscheerful(414)   (Show Source):
You can put this solution on YOUR website! To make it a little clearer, give them variables.
Jessica=JE
John=JO
Karen=KA
Before making them into equations, give yourself some examples.
For example:
If John had 5 books, Jessica would have 20 books.
If Jessica had 20 books, Karen had 4 books.
Now set up a mathematical equation
Back to your question.
If Karen had 40 books, what is the least number of books Jessica could have?
Plug 40 in for KA
So, your answer would be (e)200.
SECOND QUESTION
Same method, give variables to the people
Judy=J
Adam=A
Set up a mathematical equation
NOW: 
6 YEARS AGO: 
For this one I would try each answer:
(a)6 years ago, Judy was 4 years old. That means Adam isn't even born yet.
6 years later, Judy was 10 years old, Adam is 6 years old. DOESN'T WORK
(b)6 years ago, Judy was 10 years old. That makes Adam 2 years old.
6 years later, Judy was 16 years old and Adam is 8 years old. WORKS, BUT MUST CONSIDER ALL CHOICES
(c)6 years ago, Judy was 14 years old. That makes Adam 2.8 years old. DOESN'T WORK*
(d)6 years ago, Judy was 18 years old. That makes Adam 3.6 years old. DOESN'T WORK*
(e)6 years ago, Judy was 28 years old. That makes Adam 5.6 years old. DOESN'T WORK*
Now we can see that (b) is the only one that works.
Problems above with the * doens't mean that you can't have a decimal for an age. You can, I just wanted to save your time and did the work in my head.
Hope this helps!
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