## Wednesday, August 12, 2015

### Dentist

(Click on the comic if you can't see the full image.)

And half of a sixteenth is a "dirty-tooth"!

Some numbers transcend normal arithmetic problems.

Come back often for more funny math and geeky comics.

Anonymous said...

Hi, can you please post the Geometry Regents CC August Answers today or tomorrow the latest? Please I'm extremely worried I might have missed a few things, especially #36,(people have been telling me you have to round up the oz to 981 instead of staying at 980.2)

(x, why?) said...

I haven't seen the exam. If you can give me the specifics of a question, I can help out, but otherwise, I won't know anything until the tests are made available.

What did they ask that people are telling you to round .2 up to the next number. (Sometimes you have to round up if you are, for example, putting up fencing around a perimeter and it's only sold by the unit.)

Anonymous said...

When are the tests available? Didn't you get the algebra regents on hand the next day? Sorry if I'm a bit rude just the anxiety is uncontrollable.
ok so this is question 36, and its split into 3 parts.

1) This guy is making candles in the shape of a cone using a mold with diameter 3 and height 8. To the nearest cubic inch, how much is the volume of 100 such candles?

MY WORK: Radius = 3/2 = 1.5. V = 1/3*pi*1.5^2*8 = 6pi, 100 candles is about 1885 in^3.

part 2) He has to buy wax for his design, there are .52 oz per cubic inch, and each oz costs \$.10 to make. How much does the total wax for 100 candles cost?

MY WORK: Using a proportion, .52*1885 = 980.2 oz of wax. I then used 980.2 in the proportion to derive the cost, but classmates were saying that when you weigh, you have to round up so 980.2 = 981. My argument is that if they regents wanted you to do that, they would have specified(seriously how many 9th graders these days actually know that). Ok so i then multiplied 980.2 by .10 to get 98.02, which is the price of 100 candles.

part 3) This guy spends 37.83 on molds, and charges 1.95 for each candle. What total profit does he make?

MY WORK I assumed the total for part 2 was also accounted for in this problem(why wouldn't it, wax is an expense), so i went ahead and added 98.02 and 37.83 to get 135.85, and then subtracted that from 1.95*100 to get a total of \$59.15

(x, why?) said...

I get the tests by working at the school and proctoring and taking a copy. I get the answers by doing the test, which is why mistakes sometimes happen and then get corrected later on.

If the wax costs \$.10 for an ounce, then you need to round up to the next ounce to have enough wax. Your answer for part 2 carries over into part 3, so as long as you are consistent, you don't get penalized twice.

(x, why?) said...