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About 230 billion litres of water flows through a river each day, how many litres of water flows through that river in a week? How many litres of water flows through the river in an year? Write your answer in standard notation. |
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Answer» Given litres of water that flow through the river in a day = 230 billion = 230, 000, 000, 000 = 230 × 109 litres We know that 1 week = 7 days and 1 year = 365 days. Litres of water that flow through that river in a week = 230 × 109 × 7 = 1610 × 109 In standard notation, 1610 × 109 = 1.61 × 103 × 109 We know that by properties of exponents, am × an = am + n. ⇒ 1.61 × 103 × 109 = 1.61 × 103 + 9 = 1.61 × 101 ∴ Litres of water that flow through that river in a week = 1.61 × 1012 litres Litres of water that flow through that river in a year = 230 × 109 × 365 = 83950 × 109 In standard notation, 83950 × 109 = 8.395 × 104 × 109 We know that by properties of exponents, am × an = am + n. ⇒ 8.395 × 104 × 109 = 8.395 × 104 + 9 = 8.395 × 101 ∴ Litres of water that flow through that river in a year = 8.395 × 1013 litres |
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