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: in an electric circuit , two resistors with resistances 3 ohm and 5 ohm are connected in parallel . in this case , if r is the combined resistance of these two resistors , then the reciprocal of r is equal to the sum of the reciprocals of two resistors . what is the value ? 
Options: ['a ) 15 ohms', 'b ) 15 / 8 ohms', 'c ) 1 / 8 ohms', 'd ) 8 / 15 ohms', 'e ) 8 ohms']
b

Problem: the parameter of a square is equal to the perimeter of a rectangle of length 7.5 cm and breadth 6.5 cm . find the circumference of a semicircle whose diameter is equal to the side of the square . ( round off your answer to two decimal places ) ? 
Options: a ) 10.2 , b ) 10.27 , c ) 10.23 , d ) 10.21 , e ) 10.25
d

Problem: the area of a square is equal to seven times the area of a rectangle of dimensions 25 cm * 343 cm . what is the perimeter of the square ? 
Options: a ) 810 cm , b ) 800 cm , c ) 980 cm , d ) 718 cm , e ) 860 cm

c