According to the american heart association considerations for selecting an exercise program should be:

choose one, which is inexpensive, not costing more than $300.

be challenging to complete. no pain, no gain.

choose one that you are interested in and will be able to easily adapt.

choose one that your friends are involved in.

According to the American Heart Association considerations for selecting an exercise program should be to choose one that you are interested in and will be able to easily adapt.
It is very important that you like the exercises you are doing, otherwise, you will throw away your money for nothing and the exercises won't yield any results. 

A) for the n row: 22+(n-1)×6therefore,b) 100-22=78that means (n-1)×6=7878÷6=1313+1=1414th row has 100 seats