A certain airline's fleet consisted of 70 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?  Choose the correct choice from the following.
A) 7  B) 8  C) 9  D) 10  E) 11
Let x be the number of years.   4x &gt; 70 - 3x   7x &gt; 70   x &gt; 10   The answer is 11.
<result>E</result>
A certain airline's fleet consisted of 70 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?