In their advertisements. many employers specify that the applicant''s age should not exceed a certain age. What do you say?

Please be assured that every position has its own requirement like physical, mental or IQ/EQ and age is one of the criterion for filling position.

Agreed with all , determination of age to avoid paying high salary for those with more experiences, defiantly they will ask as per their experiences comparing with those with less experience .also some position need young energetic people therefore consideration of age is important .    

Age determines the experience of employees. If it is more, salary and other benefits will be high. For that reason, we set age for any position whatever more or less.

I agree with you but the same time it might be related to salary because older applicants will have much experience and will ask for big salary. Some companies prefer to get young with knowledge and be trained instead of getting one with experience and pay big salary