||'''Book'''|| Advanced Engineering Mathematics ||
 ||'''Author'''|| Erwin Kreyszig ||
 ||'''Edition'''|| 8th Edition ||

/* code_begins */

{{{
# radius = R
#volume 
pi = 3.1415

V = (4/3)*pi*R^3; V

#area 
A = 4*pi*R^2


#by hypothesis

#d(V)/dt = -k*A  (where k is the proportionality constant)

# d(R)/dt = -k 

# integrating this leads to, k = -0.5 cm/month

#----------

# Delta(R) = 2cm - 1mm = 1.9 cm
# Delta(R)/Delta(T) = -(-0.5)

Delta(T) = 1.9/0.5 

print Delta(T)
}}}

/* code_ends */

 * '''Solution by''': 
   * gnash, developer, space
   * bhanukiran, student, technical university of Delft
   * saransh, student, sobhit university