## Tuesday, December 21, 2010

### My Textbook Pages # 142 - 143

This scribe post about percentages will have the answers for questions no. 3, 4 and 8.

3. Use mental math to determine each of the following:

a) 300% of 2000
b) 1 1/4% of 60
c) 0.1% of 40

.

b) The answer is 0.75. How I got the answer, is that I used a ratio table to do this. So, here is my work:

c) The answer is 0.04. Once again, used a ratio table.

4. Use mental math to find the following:

a) 20% of 60
b) 250% of 400
c) 10 1/2% of 100

(Sorry if there isn't any pictures of how I showed my work. I tried to put up more, but when I kept on moving them around, the layout will mess up and I eventually end up deleting the picture when I press enter. I'm pretty sure you guys can figure how you can get these numbers by yourselves.)

8. The original price of a jacket was \$84.00. A store manager marked the price down by 25 1/2%. By how much was the price reduced?

The price has been reduced by \$21.42. How I got this answer, is that I used a ratio table to make life easier. I divided 100 by 100, to get 1, and then multiplied it by 25.5. I did the same exact thing, only, I divided 84 by 100, which gave me 0.84. Finally, when I multiplied it by 25.5, it gave me 21.42.