Congratulations to Paolina, the winner of last week’s math minute and soon-to-be recipient of a limited-edition Adopt-a-Microbe T-shirt! Thanks to all who submitted their answers this week. There are still two more chances to win, so keep calculating! Here are the answers to last week’s questions:

Monday: Throughout the ship, we use about 55 tons of water every day. Luckily, we can make and store our own fresh water. We have 3 storage tanks that hold a total of 242 tons of water. We have 3 water makers, but usually only run 1, which makes about 34 tons per day. If we started with full tanks and didn’t use the other water makers, how long would it take us to run out of water?

55 tons (used) – 34 tons (made) = 21 tons (deficit) per day

242 tons ÷ 21 tons/day = 11.52 days

We would run out of water after 11.52 days.

Tuesday: On our way to begin coring, we drilled through the cement we pumped in around the 10.75” casing. We measured 21 meters of cement in the hole, which works out to approximately 2.4 cubic meters of cement. How much of our 20 barrels ended up down at the bottom of the hole? (1 barrel = 42 gallons)

2.4 m³ x 264.2 gal/m³ = 634.08 gallons

634.08 gal ÷ 42 gal/barrel = 15.1 barrels

Approximately 15.1 barrels of the 20 barrels we pumped made it down to the bottom.

Wednesday: We have the following areas available for dry storage: #1 (cereals, crackers, noodles, pasteurized milk, etc.): 15 x 20 ft; #2 (plastic bags, foil, cups, etc.): 12 x 10 ft; #3 (canned and jarred food): 6 x 8 ft; #4 (rice, flour, food needed for that week, etc.): 12 x 12 ft. What is the total area of dry storage available?

15 ft x 20 ft = 300 ft²

12 ft x 10 ft = 120 ft²

6 ft x 8 ft = 48 ft²

12 ft x 12 ft = 144 ft²

300 ft² + 120 ft² + 48 ft² + 144 ft² = 612 ft²

We have 612 square feet of dry storage onboard.

Thursday: We have now been coring for almost 3 days here at Hole U1383C. We began coring at 69.5 mbsf (meters below sea floor), and after drilling for 32.5 hours, we are currently at 149.9 mbsf. What is the average penetration rate (meters per hour of drilling)?

149.9 m – 69.5 m = 80.4 meters

80.4 m ÷ 32.5 hrs = 2.47 m/hr

Our average rate of penetration was 2.47 meters per hour of drilling.

Friday: When we are in transit, we burn about 10,500 USG per day. It took us about 4 days to get here from Barbados. How many gallons of fuel did we burn on the way?

10,500 gal/day x 4 days = 42,000 gallons

We burned 42,000 gallons of fuel between Barbados and our study site.