Identifying the Pattern in the Number Series

We need to find the number that correctly replaces the question mark (?) in the given sequence: 94, 36, 18, ?. To solve this, we must carefully examine the relationship between the consecutive numbers in the series.

• The first term is 94.
• The second term is 36.
• The third term is 18.
• The fourth term is the unknown (?).

Let's look for a mathematical relationship between 94 and 36, and then between 36 and 18.

Initial Observation:

• Difference between 94 and 36 is $94 - 36 = 58$.
• Difference between 36 and 18 is $36 - 18 = 18$.

The differences are not constant, suggesting it's not a simple arithmetic progression. Let's explore other possibilities.

Discovering the Pattern: Product of Digits

Consider the digits of each number and see if their product relates to the next number in the series.

• For the first number, 94: Multiply its digits: $9 \times 4 = 36$. This matches the second number in the series.
• For the second number, 36: Multiply its digits: $3 \times 6 = 18$. This matches the third number in the series.

This pattern seems consistent. The rule appears to be: each subsequent number is obtained by multiplying the digits of the preceding number.

Step-by-Step Calculation

Applying the identified pattern to find the missing number:

1. Step 1: Analyze the first term (94). Calculate the product of its digits.
   Calculation: $9 \times 4 = 36$. This is the second term.
2. Step 2: Analyze the second term (36). Calculate the product of its digits.
   Calculation: $3 \times 6 = 18$. This is the third term.
3. Step 3: Analyze the third term (18). Calculate the product of its digits to find the fourth term (?).
   Calculation: $1 \times 8 = 8$.

Therefore, the number that correctly replaces the question mark (?) in the series is 8.

The complete series is 94, 36, 18, 8.