This question asks: If a stock decreases in value from $87.50 to $62.50, what is the percent change?

A) -20%
B) -25%
C) -29%
D) -38%
E) -43%

The correct answer is "C)". I left this one blank because my solution did not match any of the given solutions. I verified my results with the book's answer sheet and I realized that I made a careless mistake subtracting $87.50 from $62.50. It should have been "-25", but I had "-15". Beside this error, I am curious as to how the answer sheet converted all the numbers into fractions that we can simplify later on.

For instance, the book converted:
(-$25/$87.50) X 100%...into...
[- (2/8 X $100) / (7/8 X $100) ] 100% = -29%

My question is how valuable would it be to memorize the values of standard fractions and be able to recognize the values of standard fractions multiplied by a certain quotient (e.g. 2 and 8 in this case). Would this ability come from practice or memorization of the values of standard fractions?

It is tremendously useful to memorize standard fraction / decimal equivalents!
You should know 1/2, 1/3, 2/3, 1/4, 3/4, 1/5, 2/5, 3/5, 4/5, 1/6, 5/6, 1/7, 1/8, 3/8, 5/8, 7/8, all the ninths, and the tenths.

This will be covered in your first day of class.

Veritas Help

It's good to know the decimal equivalents of standard fractions. Thanks for pointing them out.


Matt