137. If the height of a cylinder is in-creased by 15% and the radiusof

1.	137. If the height of a cylinder is in-creased by 15% and the radiusof its base is decreased by 10%then the percentage change inits curved surface area is :(a) 2.5% increased(b) 3.5% increased(c) 2.5% decreased(d) 3.5% decreased
Answer» 3.5℅ Increase in height = 15%=3/20=3/20 Decrease in base radius = 10%=1/10Required % increase in area =7/200×100=3.5%

137. If the height of a cylinder is in-creased by 15% and the radiusof its base is decreased by 10%then the percentage change inits curved surface area is :(a) 2.5% increased(b) 3.5% increased(c) 2.5% decreased(d) 3.5% decreased

Answer»

3.5℅

Increase in height = 15%=3/20=3/20

Decrease in base radius

= 10%=1/10Required % increase in area

=7/200×100=3.5%