a) Ai de a face cu o progresie aritmetica de ratie 7 ;
a 2014 = a1 + 2013 * r => a 2014 = 3 + 2013 * 7 = 3 + 14091 = 14094;
b) x = a k < 608 => a 1 + ( k - 1 ) * r < 608 => 3 + ( k - 1 ) * 7 < 608 => k = 87 =>
x = a 87 = 605; atunci y = a 88 = 612;
Bafta !