To find the missing term in the series 2A11, 4D13, 12G17, 48J23, we need to analyze the pattern for each component of the terms: the first number, the letter, and the second number.

Analyzing the First Number Pattern

Let's look at the sequence of the first numbers: 2, 4, 12, 48, ...

• From 2 to 4: $2 \times 2 = 4$
• From 4 to 12: $4 \times 3 = 12$
• From 12 to 48: $12 \times 4 = 48$

The pattern for the first number is multiplication by a factor that increases by 1 each time (2, 3, 4, ...). So, the next multiplication factor should be 5.

The next first number is $48 \times 5 = 240$.

Analyzing the Letter Pattern

Now let's look at the sequence of letters: A, D, G, J, ...

We can determine the position of each letter in the English alphabet:

• A is the 1st letter.
• D is the 4th letter.
• G is the 7th letter.
• J is the 10th letter.

Let's find the difference in their positions:

• From A to D: $4 - 1 = 3$ (3 letters added)
• From D to G: $7 - 4 = 3$ (3 letters added)
• From G to J: $10 - 7 = 3$ (3 letters added)

The pattern for the letter is adding 3 to the position of the previous letter in the alphabet. The last letter is J (10th position).

The next letter will be at position $10 + 3 = 13$. The 13th letter of the alphabet is M.

Analyzing the Second Number Pattern

Finally, let's look at the sequence of the second numbers: 11, 13, 17, 23, ...

Let's find the difference between consecutive terms:

• From 11 to 13: $13 - 11 = 2$ (add 2)
• From 13 to 17: $17 - 13 = 4$ (add 4)
• From 17 to 23: $23 - 17 = 6$ (add 6)

The pattern for the second number is adding a value that increases by 2 each time (2, 4, 6, ...). So, the next value to add should be 8.

The next second number is $23 + 8 = 31$.

Combining the Patterns

Combining the results for each component:

• Next first number: 240
• Next letter: M
• Next second number: 31

The missing term in the series is 240M31.