Coins of same size are placed one above the other and a cylindrical solid block is formed. The volume of this block is 49.28 cm 3 . Diameter of each coin is 2.8 cm and thickness 0.2 cm. Find the number of coins arranged in the block. - Wired Faculty

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Coins of same size are placed one above the other and a cylindrical solid block is formed. The volume of this block is 49.28 cm³. Diameter of each coin is 2.8 cm and thickness 0.2 cm. Find the number of coins arranged in the block.

$open parentheses straight pi equals 22 over 7 close parentheses$

Solution

Let n be the number of coins.

For block
$straight r equals fraction numerator 2.8 over denominator 2 end fraction space cm equals 1.4 space cm straight h equals space left parenthesis 0.2 right parenthesis straight n space cm straight V equals 49.28 space cm cubed rightwards double arrow space space space space 49.28 space equals space 22 over 7 left parenthesis 1.4 right parenthesis squared space left parenthesis 0.2 right parenthesis straight n rightwards double arrow space space space straight n equals 40$

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Probability

Coins of same size are placed one above the other and a cylindrical solid block is formed. The volume of this block is 49.28 cm³. Diameter of each coin is 2.8 cm and thickness 0.2 cm. Find the number of coins arranged in the block.

$open parentheses straight pi equals 22 over 7 close parentheses$

Some More Questions From Probability Chapter

A table cover 4 m x 2 m is spread on a table. Find the cost of polishing the top of the table at र40 per square metre of 25 cm table cover is hanging all round the table.

A classroom is 7 m long, 6.5 m wide and 4 m high. It has one door 3 m x 1.4 m and three windows each measuring 2 m x 1 m. The interior wall is to be colour washed. Find the cost of colour washing at the rate of र 3.50 per m².

Two cubes of side 6 cm each, are joined end to end. Find the surface area of the resulting cuboid.

The dimensions of a rectangular box are in the ratio of 2 : 3 : 4 and the difference between the cost of covering it with sheet of paper at the rates of र 8 and र 9.50 per m² is र1248. Find the dimensions of the box.

The length, breadth and height of a cuboid are 15 cm, 10 cm and 20 cm. Find the surface area of the cuboid.

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Probability

Coins of same size are placed one above the other and a cylindrical solid block is formed. The volume of this block is 49.28 cm3. Diameter of each coin is 2.8 cm and thickness 0.2 cm. Find the number of coins arranged in the block.

Some More Questions From Probability Chapter

A table cover 4 m x 2 m is spread on a table. Find the cost of polishing the top of the table at र40 per square metre of 25 cm table cover is hanging all round the table.

A classroom is 7 m long, 6.5 m wide and 4 m high. It has one door 3 m x 1.4 m and three windows each measuring 2 m x 1 m. The interior wall is to be colour washed. Find the cost of colour washing at the rate of र 3.50 per m2.

Two cubes of side 6 cm each, are joined end to end. Find the surface area of the resulting cuboid.

The dimensions of a rectangular box are in the ratio of 2 : 3 : 4 and the difference between the cost of covering it with sheet of paper at the rates of र 8 and र 9.50 per m2 is र1248. Find the dimensions of the box.

The length, breadth and height of a cuboid are 15 cm, 10 cm and 20 cm. Find the surface area of the cuboid.

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Coins of same size are placed one above the other and a cylindrical solid block is formed. The volume of this block is 49.28 cm³. Diameter of each coin is 2.8 cm and thickness 0.2 cm. Find the number of coins arranged in the block.

$open parentheses straight pi equals 22 over 7 close parentheses$

A classroom is 7 m long, 6.5 m wide and 4 m high. It has one door 3 m x 1.4 m and three windows each measuring 2 m x 1 m. The interior wall is to be colour washed. Find the cost of colour washing at the rate of र 3.50 per m².

The dimensions of a rectangular box are in the ratio of 2 : 3 : 4 and the difference between the cost of covering it with sheet of paper at the rates of र 8 and र 9.50 per m² is र1248. Find the dimensions of the box.