What number should replace the question mark in the image below?

Question

Which number comes next in the series? 3, 6, 11, 18, 27, ?

Answer 1

Instead of multiplying up, work backward by dividing each bottom number by its top number.

Column 1 ratio: \( 48 \div 6 = 8 \).
Column 2 ratio: \( 96 \div 12 = 8 \).
Apply the same ratio to column 3: the missing top number times 8 must give 192, so divide 192 by 8 instead of guessing values.

\( 192 \div 8 = 24 \), so the question mark is 24, matching option D.

Let's summarize:

Checking the ratio between bottom and top in two known columns first confirms the rule before you use it on the missing value.

Both the multiply-up and divide-down routes land on 24.

Answer 2

Instead of multiplying up, work backward by dividing each bottom number by its top number.

Column 1 ratio: \( 48 \div 6 = 8 \).
Column 2 ratio: \( 96 \div 12 = 8 \).
Apply the same ratio to column 3: the missing top number times 8 must give 192, so divide 192 by 8 instead of guessing values.

\( 192 \div 8 = 24 \), so the question mark is 24, matching option D.

Let's summarize:

Checking the ratio between bottom and top in two known columns first confirms the rule before you use it on the missing value.

Both the multiply-up and divide-down routes land on 24.

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