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Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.

If private savings 'v' = 0.75s and total savings 's' equals $4.20 billion, solve for public and private savings.