WASHINGTON STATE MATHEMATICS COUNCIL 2000 MIDDLE SCHOOL MATH OLYMPIAD Session II: EIGHTH GRADE ALGEBRAIC SENSE Make sure you include proper units in your answer!

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1. Claude kept track of what he saw at Sea Universe Theme Park. He saw twice as many sharks as dolphins. The number of whales was 6 less than the number of sharks. There were 5 times as many sea lions as there were whales. He saw 20 sea lions. How many sea animals did Claude see all together?

2. Twelve people rent a boat. By taking 8 more people (at the same rental rate), the cost to each person is reduced by $2.50. How much is the rent for the boat?

3. The town is buzzing with the news: The Teah has returned! Everyone groans. The Teah is a water monster with an enormous thirst. It slips unseen into the favorite lake of the townsfolk and begins its work. On its first day in residence, it politely drinks only one gallon of water. The second day it drinks two gallons. The third day it consumes three gallons. The summer goes on, and the Teah keeps drinking until it has consumed 1,830 gallons of water. The next day it slips away as quietly as it came. On what day did the Teah leave the lake?

4. Find a four-digit number abcd such that if a decimal point is placed between ab and cd, (i.e., ab.cd), the resulting number is the mean of ab and cd.

5. John can complete a job in 20 days. Jean can complete the same job in 15 days. Working together they can complete the job in how many days? (Express the answer as a mixed fraction or mixed number.)