Good question:
Lets analyze it:
Survey of subscribers (people who read Systems magazine - to get a clear picture)
30% of orders in response to ads were by people under age 35.
Survey of advertisers (people who owned products)
Most of the orders in response to ads were by people under age 35.
The point is that if subscribers (under age 35) account for only 30% of the orders, who are those others under age 35 who account for the rest of the orders? (Since most of the orders were by people under age 35)
1. The comparison is not between under 35 and over 35. Most of the orders were anyway by people under 35.
2. Again, comparison is not between last year and this year. We are only talking about data of last year.
3. Not so. The survey says that most orders were placed by people under age 35.
4. We are not concerned with the dollar amount of the orders. Only the number of orders. The data says '30% of the orders...' means '30% of the total number of orders'.
5. This option says that last year, many people who placed orders in response to ads were not subscribers. Now it makes sense. Think about it. People who read Systems in a library or doc's waiting room or friend's house etc could have all placed orders in response to ads though they were not subscribers to the magazine. The rest of the 70% orders (perhaps not all but most) must have been placed by them and they must be below 35 years of age. Now it makes sense why subscribers only account for 30% of the orders.