150, 143, 129, 108, ? 45

Options

A. 96
B. 90
C. 85
D. 80

Explanation

To find the missing number in the series: 150, 143, 129, 108, ?, 45, we will analyze the differences between the numbers step by step.

### Step 1: Identify the differences between consecutive numbers.
- The first difference: 150 - 143 = 7
- The second difference: 143 - 129 = 14
- The third difference: 129 - 108 = 21

### Step 2: Observe the pattern in the differences.
The differences we calculated are:
- 7
- 14
- 21

We can see that these differences are increasing by 7 each time:
- 14 - 7 = 7
- 21 - 14 = 7

### Step 3: Predict the next difference.
Following the pattern, the next difference should be:
- 21 + 7 = 28

### Step 4: Calculate the missing number.
Now, we will subtract this next difference from the last known number in the series (108):
- Missing number = 108 - 28 = 80

### Step 5: Verify the next number in the series.
Now, we will check the difference between the missing number (80) and the next number (45):
- 80 - 45 = 35

### Conclusion:
The missing number in the series is **80**.