Answer:
Step-by-step explanation:
Find the GCD of 
:
So the prime factor common to 6, 8 is:
So the factor common to :
If he spent half his savings on supplies and the other half on lunch he shouldn't have money left over. It's a trick question.
Is there an A.B.C. or D to choose from?
I'll do the first two problems to get you started. All problems shown will use the same formula.
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Problem 4
The formula to use is
C = 100*(B-A)/A
where
A = old value
B = new value
C = percent change
In this case, A = 12 and B = 36, so
C = 100*(B-A)/A
C = 100*(36-12)/12
C = 100*(24/12)
C = 100*2
C = 200%
We have a 200% increase. It is an increase because the value of C is positive.
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Problem 5
Use the same formula as in the previous problem. This time,
A = 75 is the old value
B = 25 is the new value
C = 100*(B-A)/A
C = 100*(25-75)/75
C = 100*(-50/75)
C = 100*(-2/3)
C = -66.6667%
C = -66.7%
The value of C is negative, so we have a percent decrease of roughly 66.7%
