Q18 of 35 Page 74

The length and breadth of a rectangular field of the village are 20m and 15 m respectively.For the construction of pillars in the 4 corners of that field 4 cubic holes having the depth of 4 m are dug out and the soils removed are dispersed on the remaining land. Let us calculate and write the height of the surface of the field that is increased by.

Let the height to be increased = H m

Given, length of rectangular field = 20m.


breadth of rectangular field = 15m.


edge of each cubic hole = 4m


total no. of cubic holes = 4


According to the question,


Total volume of soil dug out of 4 cubical holes = volume of soil deposited on rectangular field.


4×43 = 20×15×H


⇒ 256 = 300H


H = 0.853 m


More from this chapter

All 35 →
16

If the length, breadth, and height of one packet of one gross match box are 2.8dcm. and 0.9dcm respectively, then let us calculate the volume of one match box. [one gross=12dozen]. But if the length and breadth of one matchbox be 5 cm and 3.5 cm , then let us calculate the height of it.

 17

Half of the cuboidal water tank with length of 2.1 m and breadth of 1.5 m is filled with water. If 630 lt of water is poured more into the tank, then let us calculate and write the depth that will be increased by.

 19

For elevating 6.5dcm of a low land with length of 48m and breadth of 31.5m , it is decided that the soil will be collected by scooping a hole in a nearby land with a length of 27m and breadth od 18.2m, let us calculate the depth of the hole in the metre.

 20

There were 800L, 725L and 575 L kerosene oil in 3 kerosine oil drums of the house. The oil of these 3 drums is poured into a cubical pot and for this, the depth of the drum becomes 7dcm.If the ratio of the length and breadth of the cuboidal pot is 4:3 then let us write by calculating the length and breadth of the pot.

If the depth of the cuboidal pot would be 5 dcm, let us calculate whether 1620 L oil can be kept or not in that pot.