the average age of a family of 5 members is 20 years . if the age of the youngest member be 10 years then what was the average age of the family at the time of the birth of the youngest member ?
n0 = 5.0
n1 = 20.0
n2 = 10.0
t0 = n0 * n1
t1 = t0 - n2
t2 = t1 / 4.0
answer = t2 - n2
print(answer)