A number is missing from the number series below.
Can you find it ?
84, ?, 258, 399 , 584, 819.  Choices:
A) 155
B) 350
C) 399
D) 421
E) 449
A   The missing number is 155.   84 = 4^3 + 3^2 + 4   258 = 6^3 + 6^2 + 6   399 = 7^3 + 7^2 + 7   584 = 8^3 + 8^2 + 8   819 = 9^3 + 9^2 + 9   Thus,   155 = 5^3 + 5^2 + 5
<result>A</result>
A number is missing from the number series below.
Can you find it ?
84, ?, 258, 399 , 584, 819.