Multiple choice

Find the missing number in the given below series. 36 \quad 19 \quad 20 \quad 31 \quad 63 \quad 158.5 \quad ?

  1. 476.5

  2. 462

  3. 455.6

  4. 488

  5. 487.5
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The pattern alternates between two operations: first (x÷2+1), then (x+1). For 36: 36÷2+1=19, then 19+1=20, then 20÷2+1=11 (not shown). The series actually follows: 36→19 (÷2+1), 19→20 (+1), 20→31 (÷2+1), 31→63 (+1), 63→31.5 (÷2+1), 31.5→63 (+1)... Wait, let me recalculate: 36÷2+1=19, 19+1=20, 20÷2+1=11... This doesn't match. The actual pattern is: (÷2+1), (+1), (2x-9), (2x+1), (2x+32.5). For 158.5: (158.5×2)+32.5=317+32.5=349.5? No. Let me verify: 63×2.5-?=158.5. 63×2.5=157.5, so +1. The pattern involves doubling with different addends.

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