Level 3 A rectangular tank is filled with water to a height of 4 cm. Its rectangular base measures 25 cm by 8 cm. When 12 litres of water are poured into the tank, the water level rises to 25 of the height of the tank. Find the height of the tank.
Level 2
Poles are placed at equal distances along a street. The distance between any two poles is 90 cm. If the street is 2340 m long, how many poles are needed altogether?