Question

How many coins of 1.4 cm in diameter and 0.4 cm
thick are to be melted to form a right circular cylinder
of height 16 cm and diameter 3.5 cm?
A. 400
B. 250
C. 180
D. 230​

Answer 1

Answer:

C 180

Step-by-step explanation:

Hope it would be correct.

Answer 2

250 coins of 1.4 cm in diameter and 0.4 cm  thick are to be melted to form a right circular cylinder  of height 16 cm and diameter 3.5 cm

Step-by-step explanation:

Diameter of coin = 1.4 cm

Radius of coin = $\frac{1.4}{2}=0.7 cm$

Height of coin  = 0.4  m

Volume of coin = $\pi r^2h = \frac{22}{7} \times 0.7^2 \times 0.4$

Height of cylinder = 16 cm

Diameter of cylinder = 3.5 cm

Radius of cylinder = $\frac{3.5}{2}=1.75cm$

Volume of cylinder $= \pi r^h = \frac{22}{7} \times 1.75^2 \times 16$

No. of coins are to be melted to form a right circular cylinder  of height 16 cm and diameter 3.5 cm = $\frac{\frac{22}{7} \times 1.75^2 \times 16}{\frac{22}{7} \times 0.7^2 \times 0.4}=250$

Hence 250 coins of 1.4 cm in diameter and 0.4 cm  thick are to be melted to form a right circular cylinder  of height 16 cm and diameter 3.5 cm

#Learn more:

A metallic cylinder with height 20cm and the diameter of the base 56cm is melted to make smaller cylinder of radius 7cm and height is 5cm. how many cylinder can be made.

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