# IGCSE Mathematics Paper-1: Specimen Questions with Answers 16 - 16 of 324

## Question 16

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### Describe in Detail

Essay▾The table above gives the lengths of the rivers, correct to 2 significant figures.

Rivers | Length () |

Nile | |

Amazon | |

Yangtze | |

Yellow River |

(a) List the rivers in order of length, largest to smallest.

________ > ________ > Yangtze > ________.

(b) Use a whole number to complete the statement in the answer space.

The length of Amazon is approximately ________ times the length of Yellow River.

### Explanation

Here, correct the lengths of the rivers to 2 significant figures:

- Length of Nile will be:
**6,900km**because after second significant digit 8 there is 5, so 8 will be rounded and be 9. - Length of Amazon will be:
**7,000km**because after second significant digit 9 there is 9 which is greater than 5, so 69 will be rounded and be 70. - Length of Yangtze will be:
**6,300km**which has already 2 significant figures. - Length of Yellow River will be:
**5,500km**because after second significant digit 4 there is 6 which is greater than 5, so 4 will be rounded and be 5.

(a) Here, list of rivers as per largest to smallest lengths as below:

**Amazon > Nile > Yangtze > Yellow River**

Because

(b) Here, length of Amazon by using whole number is:

Length of Yellow River by using whole number is:

So, the length of Amazon is approximately **1.2** times the length of Yellow River.

**(****Calculation:** **)**