Question

please give me answer of maths question 5​

Answer 1

Answer:

400 cins

Step-by-step explanation:

volume of the cuboid= 5.5*10*3.5

                                   = 192.5

volume of a single coin= pi*r^2*h

                                      = 3.14 * (0.875)^2 * 0.2

                                      =0.4808125

∴Number of coins needed= volume of cuboid/volume of a coin

                                           = 192.5/0.4808125

                                            =400.36

                                            = 400

Answer 2

$\huge \fbox \purple{question}$

How many silver coins, 1.75 cm. in diameter and of thickness 2 mm, must be melted to form a cuboid of dimensions 5.5 cm × 10 cm × 3.5 cm ?

$\huge \orange{solution}$

Diameter of silver coins is 1.75 cm.

Thickness = 2 mm.

Measurement of cuboid: 5.5 × 10 × 3.5 cm.

∴ Let the required silver coins be ‘n’,

Volume of ‘n’ coins = Volume of cuboid

$\pi r {}^{2} h = lbh$

$n \times (\pi \times ( \frac{1.75}{2} ) {}^{2} \times 0.2) = 5.5 \times 10 \times 3.5$

$n \times \frac{ 22}{7} \times \frac{175}{200} \times \frac{2}{10} = 55 \times \frac{35}{10}$

$n \times \frac{22}{7} \times \frac{7}{8} \times \frac{7}{8} \times 2 = 55 \times 32$

$n = \frac{55 \times 35 \times 16}{7 \times 11}$

$n = 5 \times 5 \times 16$

∴ n = 400

∴ 400 silver coins are required.