Quote:
In 1990 850 million movie tickets were sold in the United States. One fifth of those tickets were bought by people over the age of 50. Did people under the age of 20 buy more than 425 million movie tickets in 1990?
(1) In 1990, people under the age of 20 bought between two and three times as many tickets as were bought by people over the age of fifty.
(2) In 1990, people under the age of 20 spent $2.2 billion more on movie tickets than did people over the age of 50, with both groups spending an average (arithmetic mean) of $6 per ticket.
(1) In 1990, people under the age of 20 bought between two and three times as many tickets as were bought by people over the age of fifty: insufic.
over 50 = 850/5 = 170M tickets… 2 (over 50) ≤ under 20 ≤ 3 (over 50)… 340M ≤ under 20 ≤ 510M
(2) In 1990, people under the age of 20 spent $2.2 billion more on movie tickets than did people over the age of 50, with both groups spending an average (arithmetic mean) of $6 per ticket: sufi.
under 20 spending - over 50 spending = 2200M
x*$6 - 170M*6 = 2200M… x = 2200M/6 + 170… x = (2200+1020)/6 =~ 531M > 425M
Answer (B)