Multiple choice

The weight of a sequence a0, a1,…, an-1 of real numbers is defined as a + a1 / 2 + …. + an-1 / 2n-1. A subsequence of a sequence is obtained by deleting some elements from the sequence, keeping the order of the remaining elements the same. Let X denote the maximum possible weight of a subsequence of a0, a1, …., an-1. Then X is equal to

  1. max (Y, a0 + Y)

  2. max (Y, a0 + Y/2)

  3. max (Y, a0 +2Y)

  4. a0 + Y / 2

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation