6 9 ? 24 36 A) 15 B) 16 C) 17 D) 18 E) 20

To find the missing number in the sequence 6, 9, ?, 24, 36, we can look for a pattern.

First, let's examine the differences between the numbers:

• From 6 to 9: difference of 3
• From 9 to ?: unknown difference
• From ? to 24: unknown difference
• From 24 to 36: difference of 12

Now, let's look at the relationship between these numbers:

The sequence appears to multiply by certain factors.

• 6 to 9: 6 * 1.5 = 9
• 9 to ?: Let's assume it is x. If we try to keep a similar ratio:
• From x to 24: x * 2.67 ≈ 24 (which would mean x would have to be around 9)

Now, to test the pattern slightly differently, we can also try to observe the sequence of multiplication:

9 is obtained by adding 3 to 6. If we add the next increment:

• 9 + 6 = 15
• Then 15 * 1.6 = 24 So if we take the next item in the series to be 15,
• 15 * 1.6 = 24, which is accurate as seen in the progression.

Therefore, the missing number is 15.

The answer is A) 15.