In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: two spherical balls lie on the ground touching . if one of the balls has a radius of 10 cm , and the point of contact is 12 cm above the ground , what is the radius of the other ball ( in centimeters ) ? 
Options: a ) 14 , b ) 15 , c ) 16 , d ) 18 , e ) 20

A: b
****
Q: Problem: two taps a and b can fill a cistern in 12 minutes and 18 minutes respectively . they are turned on at the same time . if the tap a is turned off after 4 minutes , how long will tap b take to fill the rest of the cistern ? 
Options: a ) 8 min . , b ) 9 min . , c ) 10 min . , d ) 7 min . , e ) none of these

A: a
****
Q: Problem: the length of a rectangular plot is 20 metres more than its breadth . if the cost of fencing the plot @ rs . 26.50 per metre is rs . 9540 , what is the length of the plot in metres ? 
Options: a ) 20 , b ) 200 , c ) 300 , d ) 400 , e ) 100

A:
e
****