# solve 19 and 23 no.

solve 19 and 23 no. 5 m by 4 m by
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g. Acubeof a metal of 6 an edge is melted and cast into a cuboid
fieareaofaplayground is 4800m2. Find the cost •thgtavellcmdeep,
if die gravel costs ? 260 per cubic metre.
A field is 30 m long and 18 m broad. A pit 6 m long, 4 m wide and 3 m deep is dug out
from the middle Of the field and the earth removed is evenly spread over the remaining
area of the field. Find the rise in the level of the remaining part of the field in centimetres
correct to two decimal places.
A tectangular plot is 24 m long and 20 m wide. A cubical pit of edge 4 m is dug at each
Of the four corners Of the field and the soil removed is evenly spread over the remaining
part Of the plot. By what height does the remaining plot get raised?
2k inner dimensions Of a closed wooden box are 2 m, m and •75 m. The thickness of
the wood is 2•5 cm. Find the cost Of wood required to make the box if 1 rn3 of wocki
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A Cubical wooden box Of internal edge 1 m is made of 5 cm thick wood. The box is open
at the top. If the wood costs Z 9600 per cubic metre, find the cost of the wood required to
A square brass plate of side X cm is 1 mm thick and weighs 4725 g. If one cc of brass
cubes whose edges are x an, 8 cm and 10 are melted and recast
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19.

area of the plot = 30 x 18 = 540 m

top area of the pit = 6 x 4 = 24 m

now, base area of the left over plot = 540 - 24 =516 m

volume of the pit = 6 x 4 x 3 = 72 m

now, volume of pit = volume of earth added over the plot = 72 m

or, 72 = base area of the left over plot x height of earth

or, 72 = 516 x height of earth

or, height of earth = 72 / 516 = 0.139 =0.14 m

area of the plot = 30 x 18 = 540 m

^{2}top area of the pit = 6 x 4 = 24 m

^{2}now, base area of the left over plot = 540 - 24 =516 m

^{2}volume of the pit = 6 x 4 x 3 = 72 m

^{3}now, volume of pit = volume of earth added over the plot = 72 m

^{3}or, 72 = base area of the left over plot x height of earth

or, 72 = 516 x height of earth

or, height of earth = 72 / 516 = 0.139 =0.14 m

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