The length and breadth of a rectangular field are 51m and 30m respectively. A tank of length 8m, breadth 7m and depth 5m is dug out at the middle of the field. The earth removed is evenly spread over the remaining part of the field. Find the approximate rise in the level of the remaining part of the field?
Volume of the earth dug out = 8×7 ×5 = 280 m³ The upper surface area of the field = 8×7 = 56 m² Total surface area of the field = 51×30 = 1530 m² Remaining area of the field = (1530 – 56) = 1474 m² ∴ Rise in the level of the remaining part of the field = 280/1474m = 28/1474×100cm= 18.99 cm ∼19cm
