A: An area of ‘extensive commercial grain farming’ – The Prairies, USA.
B: A terminal station of ‘Trans-Siberian Railway’ – Vladivostok, Russia.
C: An area of ‘nomadic herding’ – Sahara Desert, Africa.
D: An area of ‘commercial livestock rearing’ – Pampas, Argentina.
E: A major sea port of Asia – Shanghai, China.
F: A major international airport of Europe – Heathrow, London.
G: A major shipping canal – Suez Canal, Egypt.


A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:
(iii) (b) If the foot of the ladder, whose length is 5 m, is being pulled towards the wall such that the rate of decrease of distance \( y \) is \( 2 \, \text{m/s} \), then at what rate is the height on the wall \( x \) increasing when the foot of the ladder is 3 m away from the wall?