Fermi Questions Marathon

[Schrodingerscat]

How many times has the SAT been taken in the past 5 years?

I will again start from 3E8 Americans, but assume its somewhere less 2% of Americans are in a particular year of high school , so I will go with 5E6. Some take it once, some take it several times, but if I go ahead and multiply by the 5 years, I will get 2E7 (again rounding down assuming underestimate on the first), so assuming the number per student is the zeroth magnitude, I will go with 7.

How many tons of steel sank into the Pacific ocean with ships during World War II?

[hmcginny]

The average ship contains E1 tons of steel and maybe E4 ships sunk in the pacific ocean. So i'll say E5 tons of steel total.

If you hollowed out the earth and filled it with black bears, how many black bears would fit? (Assume the bears are whole, so no crushing bears to fit more in)

[Marble101]

The average ship contains E1 tons of steel and maybe E4 ships sunk in the pacific ocean. So i'll say E5 tons of steel total.

If you hollowed out the earth and filled it with black bears, how many black bears would fit? (Assume the bears are whole, so no crushing bears to fit more in)

Let's assume the black bears can stand in nice orderly rows with their hands at their sides Xp

I think the radius of the Earth is 4E3 km.
This is 4E6 km.
Volume is 4/3 pi r^3, pi is about 3, so that makes 4(4E6)^3, or 4(64E18), so 256E18, so about 3E20 cubic meters.
Each black bear is about 1 meter * 1/2 meter * 2 meters, or 1 cubic meter of volume.
This makes 3E20 my answer.

How many times is an emoticon used everyday in emails?

[ionocraft]

If 1/4 of the worlds population uses email (1.75 x 10E9), and 1/10 of email users use emoticons everyday, then my answer is E8.
My question is ..... How many fish are eaten by Maldivens in a year?

[cngu23]

If 1/4 of the worlds population uses email (1.75 x 10E9), and 1/10 of email users use emoticons everyday, then my answer is E8.
My question is ..... How many fish are eaten by Maldivens in a year?

There are 3E5 People living in the Maldives. They each each 1 fish a day, so about 4E2 fish a year. 1E10 Fish per year by the whole population.

My Question: How many "Hello"s are said each day by the people living in the city of Grand Rapids, Michigan.

[Angstrom]

Without looking it up, I'd say 700,000 people live there (I haven't heard of it but you called it a city). The shakier assumption is that each person says 2 hellos a day, but either way it's E7.

How many carbon atoms are there in periods in Dummies books worldwide?

[hmcginny]

So there are E2 different dummies books and maybe E6 of each book so E8 books. Each book is E2 pages with probably +E1 periods per page. So thats +E3 periods per book and +E11 periods total, i'll round to E12 cause there are definitely more than 100 dummies books. Now the hard part how many carbon atoms in a period. Lets call each period E-4 moles of carbon since periods of ink have very little mass and E-3 grams seems about right. So then there are -E20 atoms (6E19) per periods and E32 carbon atoms total.

How much does the Golden Gate Bridge weigh in femtograms?

[OldSpice]

So there are E2 different dummies books and maybe E6 of each book so E8 books. Each book is E2 pages with probably +E1 periods per page. So thats +E3 periods per book and +E11 periods total, i'll round to E12 cause there are definitely more than 100 dummies books. Now the hard part how many carbon atoms in a period. Lets call each period E-4 moles of carbon since periods of ink have very little mass and E-3 grams seems about right. So then there are -E20 atoms (6E19) per periods and E32 carbon atoms total.

How much does the Golden Gate Bridge weigh in femtograms?

a femtogram is E-15 grams
then I'm going to assume that the golden gate bridge is about a half mile long, so about 800m long.
then I'm going to assume it's 100m tall, and 20m wide.
For calculation purposes let's assume it's a rectangular prism, so its volume is about E6 meters cubed.
I will then half that, as it's obviously not a rectangular prism, so its E5 meters cubed.
I'm pretty sure, correct me if I'm wrong, that the bridge is namely made of steel, and I think one cubic meter of steel is around E4 kilograms.
So it would weigh E9 kilograms, E12 grams, and then E27 femtograms.
I could be pretty off, I assumed a lot of information there.

How many trees are there in New York State?

[Lily Essence]

( I know this is off topic, and completely out there, but I just wanted to say that I've spent the past 20 minutes just reading through this thread and it absolutely just fascinates me. Maybe I'll pick up this event next year or something. Keep up the awesome math, guys!

PS: How much oxygen is lost (due to cutting trees) every year to supply Science Olympians with rule manuals and field guides? )

[Angstrom]

Assume New York State is 50% covered in forestry (i.e. it doesn't matter), furthermore assume there is a tree in each 6m by 6m square. New York state is about a sixth the size of TEXAS, which is about the size of a 600mi square, so (600mi/6m)^2 / 12 trees. 6m is 20 ft, and 1 mi = 5280 ft = 5000 ft = 250 * (20 ft), so (600 * 250)^2 / 12 = (300 * 250)^2 / 3 = (750 * 100)^2 / 3 = (1000 * 100)^2 trees (about), so 1E10.

I don't know where to start on Lily's question. It's a great one, but I'll work later. (I just got 22nd at an invitational on this event and perhaps I should learn how to format answers before I keep on learning how to compute them).