Question

Long-Answer Questions
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17. From a solid cylinder whose height is 15 cm and diameter 16 cm, a
conical cavity of the same height and same diameter is hollowed out.
18. A solid rectangular block of dimensions 4.4 m, 2.6 m and 1 m is cast into
Find the total surface area of the remaining solid. [Use T =
a hollow cylindrical pipe of internal radius 30 cm and thickness 5 cm
Find the length of the pipe.
19. An open metal bucket is in the shape of a frustum of a cone, mounted on
a hollow cylindrical base made of the same metallic sheet. The
diameters of the two circular ends of the bucket are 45 cm and 25 cm
the total vertical height of the bucket is 40 cm and that of the cylindrical
base is 6 cm. Find the area of the metallic sheet used to make the bucket
Also, find the volume of water the bucket can hold, in litres.
20. A farmer connects a pipe of internal diameter 20 cm from a canal into a
cylindrical tank which is 10 m in diameter and 2 m deep. If the water
flows through the pipe at the rate of 4 km/hr, in how much time will
the tank be filled completely?
data
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Answer 1

Step-by-step explanation:

17)Ans....Radius= Diameter/2 =16/2Radius=8cm

Height=15cm

Slant height of cone,l=√ h2 + r2

l=√ (15)2 + (8)2

l=√ 225 + 64=√ 289

l=17cm

Total surface area of remaining solid= Curved surface area of cone

+ Curved Surface area of cylinder+ Area of bottom part

Total surface area=πrl + 2πrh + πr2

=3.14 [8 × 17 + 2 × 8 × 15 + 8 × 8]

=3.14 [440] =1381.6cm2