complete the following series
10, 15, 30, 45, 90, ….

Options

A. 100
B. 110
C. 125
D. 135

Explanation

To complete the series 10, 15, 30, 45, 90, we will analyze the pattern in the series step by step.

### Step 1: Identify the series
The given series is:
10, 15, 30, 45, 90, ...

### Step 2: Look for a pattern
Let's examine the relationship between the numbers:
- The first number is 10.
- The second number is 15, which is 10 + 5.
- The third number is 30, which is 15 × 2.
- The fourth number is 45, which is 30 + 15.
- The fifth number is 90, which is 45 × 2.

### Step 3: Identify the operations
From the above observations, we can see that:
- The series alternates between adding a number and multiplying by a factor.
- Specifically, we add 5 to get from 10 to 15, then multiply by 2 to get from 15 to 30, then add 15 to get from 30 to 45, and finally multiply by 2 to get from 45 to 90.

### Step 4: Predict the next number
Following the established pattern, after multiplying by 2 to get 90, we should now add the next number in the series:
- The last addition was 15 (from 30 to 45), so we will add 45 (the last number before 90) to 90.

Calculating this:
90 + 45 = 135

### Conclusion
Thus, the next number in the series is 135.

### Final Answer
The completed series is:
10, 15, 30, 45, 90, 135

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