Question

Look carefully for the pattern, and then choose which number comes next:
20, 110, 210, 320, _ _ _

• A. 454
• B. 452
• C. 440
• D. 461
• E. 425

Hint:

If the first-level differences aren't constant, check the "difference of differences"—this is a common feature in quadratic sequences.

Answer 1

The Correct Option is C

Concept: Find the difference between consecutive terms to see if the rate of change is constant or follows a sub-pattern.
Step 1: Calculate first-level differences.
• $110 - 20 = 90$
• $210 - 110 = 100$
• $320 - 210 = 110$

Step 2: Identify the pattern in differences.
The differences are increasing by 10 each time ($90, 100, 110$).

Step 3: Calculate the next term.
The next difference should be $110 + 10 = 120$. Next term = $320 + 120 = 440$.