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# How Many Coins 1.75cm in Diameter and 2mm Thick Must Be Melted to Form a Cuboid 11cm X 10cm X 75cm___? - CBSE Class 10 - Mathematics

ConceptVolume of a Combination of Solids

#### Question

How many coins 1.75cm  in diameter and 2mm thick must be melted to form a cuboid 11cm x 10cm x 75cm___?

#### Solution

Given that dimensions of a cuboid 11cm x 10cm x 75cm

So its volume (V1) = 11cm x 10cm x 7cm

= 11 x 10 x 7cm3         ..........(1)

Given diameter (d) = 1.75cm

Radius (r)=d/2=1.75/2=0.875cm

Thickness (h) =2mm = 0.2cm

Volume of acylinder =pir^2h

V_2=pi(0.875)^2(0.2)cm^3   ........(2)

V1 = V2 x n

Since volume of a cuboid is equal to sum of n volume of ‘n’ coins

n =V_1/V_2

n = no of coins

n=(11xx10xx7)/(n(0.875)^2(0.2))_

n = 1600

∴No of coins (n) = 1600

Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Solution for 10 Mathematics (2018 to Current)
Chapter 14: Surface Areas and Volumes
Ex. 14.10 | Q: 19 | Page no. 28
Solution How Many Coins 1.75cm in Diameter and 2mm Thick Must Be Melted to Form a Cuboid 11cm X 10cm X 75cm___? Concept: Volume of a Combination of Solids.
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