CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

How many coins 1.75 cm in diameter and 2 mm thick must be melted to form a cuboid 11 cm×10 cm×7 cm ?


Solution

 A coin is a cylinder of diameter 1.75 cm and thickness (height of cylindrical shaped coin) is 

2 mm.

radius of coin=1.752cm

and height of coin=210=0.2cm

∴ Volume of 1 coin = Volume of cylinder =πr2h=π×(1.752)2×0.2 cm3

Dimension of cuboid are 11 cm, 10 cm and 7 cm

∴ Volume of cuboid =l×b×h=70×11×7=770 cm3

According to question given,

Volume of cuboid = Number of coins × Volume of each coin

 =>770=No of coins×π×(1.752)2×0.2 cm3

 =>No of coins=770227×(1.752)2×0.2

 =770×7×422×(1.75)2×0.2=9800.2×3.0625=1600

Hence, 1600 coins are required to form a cuboid of given dimensions.

flag
 Suggest corrections
thumbs-up
 
0 Upvotes


Similar questions
View More


Same exercise questions
View More



footer-image