I took a written exam of a forigen company with my girlfriend yesterday!
these is a question i don`t know how to answer! every brothers ,help me to see see!
Two math grads ran into each other in a shopping center! they haven`t seen each other for over 20 years.
The first grad:oh,haven`t seen you for a long time,how are you?
The second grad:yes ,i married during these time,and have three children.
first:how old are they?
second:well ,the product（乘积） of these ages is 72 and sum is the number on that building over there......
first:en,,ok ,,but ,i still don`t know !
second :oh,,sorry,forget to tell you the oldest child is just beginning to play piano.
first: really ,i see now.i aslo have a daughter,her age is the same with your oldest child.
question:how old is the first man`s child? please give the reason,and which information is useless?
