Final answer:
The next number in the sequence is found by adding 10 to the last term (20), which gives us 30. This is because the sequence's differences are increasing by 2 each time.
Step-by-step explanation:
The student's question is about finding the next number in the sequence: 2, 6, 12, 20. To determine the pattern, we observe that the difference between successive terms is increasing by 2 each time. Starting with 2, the sequence of differences goes 4, 6, 8, and so on. So the next difference should be 10. Adding 10 to the last number in the sequence (20) will give us the next number in the sequence.
If we sum 20 + 10, the result is 30. Therefore, the correct answer is d) 30.