CIE Mathematics Paper-1: Specimen Questions 31 - 32 of 175

Question number: 31

Essay Question▾

Describe in Detail

On a journey a train takes 30 minutes to travel the first 20 kilometers. It then travels a further 40 kilometers in the next 50 minutes.

(a) The train started the journey at 13: 45. At what time did it complete the journey?

(b) Calculate the average speed of the whole journey in

(i) kilometers/minute,

(ii) kilometers/hour.

Explanation

Here, train takes 30 minutes to travel the first 20 kilometers. It then travels a further 40 kilometers in the next 50 minutes.

(a) Train started the journey at 13: 45.

It takes total 30+50=80minutes=1hourand20minutes.

So, it had completed the journey at 13: 45 + 1 hour + 20 minutes = 14: 45 + 20 minutes = 14: 45 + 15 minutes + 5 minutes = 15: 05.

(b) Here total distance = 20+40=60kilometers

Total time = 30+50=80minutes

(i) Average speed = totaldistancetotaltime=6080=0.75kmm

(ii) 60 minutes = 1 hour

80 minutes =? hours

80×160=1.33 hours

So, average speed = totaldistancetotaltime=601.33=45.11kmh.

Question number: 32

Essay Question▾

Describe in Detail

The table above gives the areas of forests of different countries, correct to 4 significant figures.

The table above gives the areas of forests of different countries,

In detail The table above gives the areas of forests of different countries,

Forests of Countries

Area ( km2 )

Russia

7,762,602

Brazil

4,776,980

Canada

3,101,340

United States

3,030,890

(a) List the Forests of Countries in order of area, smallest to largest.

________ < Canada < ________ < ________.

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

The area of forests of Russia is approximately ________ times the area of forests of Canada.

Explanation

Here, correct the area of the countries to 4 significant figures:

  • Area of forest of Russia will be: 7, 763, 000 km2 because after fourth significant digit 2 there is 6 which is greater than 5, so 2 will be rounded and be 3.
  • Area of forest of Brazil will be: 4, 777, 000 km2 because after fourth significant digit 6 there is 9 which is greater than 5, so 6 will be rounded and be 7.
  • Area of forest of Canada will be: 3, 101, 000 km2 because after fourth significant digit 1 there is 3 which is less than 5, so 1 will remain same.
  • Area of forest of United States will be: 3, 031, 000 km2 because after fourth significant digit 0 there is 8 which is greater than 5, so 0 will be rounded and be 1.

(a) Here, list of countries as per smallest to largest areas as below:

United States < Canada < Brazil < Russia

Because 3,030,890<3,101,340<4,776,980<7,762,602

(b) Here, area of forests of Russia by using whole number is: 7,762,602km2

Area of forests of Canada by using whole number is: 3,101,340km2

So, the area of forests of Russia is approximately 2.5 times the area of forests of Canada.

( Calculation: 3,101,340×2.5=7,753,350~7,762,602km2 )

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