5,9,18,30,50,__\nOptions:\n(A) 79\n(B) 80\n(C) 81\n(D) 82\n(E) 83
Let’s work this out in a step by step way to be sure we have the right answer.
(E)
(9+5) +4 = 18\n(16+9) +5 = 30\n(28+16)+6 = 50\n(48+28)+7 = 83.

So, the final answer is (E)