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Line 365:
Line 365: − + − + − =2Лrh+ Л+ − = 2XX5X14+X+ − =440+78.5+ − =518.5 + − + − + − =2.1777 +
→Mensuration
# addition and multiplication of fractions
# addition and multiplication of fractions
#unit of area
#unit of area
solution: r=5cm, h=14cm, Л=
solution: r=5cm, h=14cm, Л=<math>{\frac{22}{7}}</math><br>
Curved surface area of cylinder and area of one circle= CSA of cylinder+area of circle
Curved surface area of cylinder and area of one circle= CSA of cylinder+area of circle<br>
=<math>2Лrh+Лr^2</math><br>
=<math>2X{\frac{22}{7}}X5X14+{\frac{22}{7}}X{5^2}</math><br>
=440+78.5<br>
=518.5cm
Cardboard required to prepare 42 penstands= 42X518.5=21777
Cardboard required to prepare 42 penstands= 42X518.5<br>
=<math>21777{cm^2}</math><br>
=<math>2.1777{m^2}</math><br>