TASK DEFINITION: In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
PROBLEM: Problem: the radius of a cylinder is 2 r units and height is 3 r units . find the curved surface ? 
Options: a ) 18 π r 2 , b ) 12 π r 2 , c ) 3 π r 2 , d ) 6 π r 2 , e ) 9 π r 2

SOLUTION: b

PROBLEM: Problem: the length of a rectangle is halved while its width is also halved . what is the % change in area ? 
Options: a ) 25 % , b ) 30 % , c ) 50 % , d ) 65 % , e ) 75 %

SOLUTION: e

PROBLEM: Problem: what is the percentage increase in the area of a rectangle , if each of its sides is increased by 20 % ? 
Options: a ) 42 % , b ) 43 % , c ) 45 % , d ) 44 % , e ) 46 %

SOLUTION:
d