A certain airline's fleet consisted of 110 type A planes at the beginning of 1980. At the end of each year, starting with 1980, the airline retired 3 of the TYPE A planes and acquired 4 new type B plans. How many years did it take before the number of type A planes left in the airline's fleet was less than 50 percent of the fleet?
Pick one:  A) 15  B) 16  C) 17  D) 18  E) 19
Let x be the number of years.   4x &gt; 110 - 3x   7x &gt; 110   x &gt; 15 + 5/7   The answer is 16.
<result>B</result>
A certain airline's fleet consisted of 110 type A planes at the beginning of 1980. At the end of each year, starting with 1980, the airline retired 3 of the TYPE A planes and acquired 4 new type B plans. How many years did it take before the number of type A planes left in the airline's fleet was less than 50 percent of the fleet?