In each of these questions a number series is given. In each series only one number is wrong. Find out the wrong number: 1401, 1402, 706, 244, 77.

Steps to Solve

1. Identify the relationship between numbers

Observe how the numbers relate to one another. Here, look for patterns such as addition, subtraction, multiplication, or division.

2. Calculate the ratios or differences

Look at the differences or ratios between consecutive numbers:

• From 1401 to 1402, the difference is $1402 - 1401 = 1$.
• From 1402 to 706, the difference is $706 - 1402 = -696$.
• From 706 to 244, the difference is $244 - 706 = -462$.
• From 244 to 77, the difference is $77 - 244 = -167$.

3. Analyze the differences

The differences between the numbers seem inconsistent. The differences are:

• $1$, then $-696$, then $-462$, then $-167$.

Since the values decrease dramatically between 1402 and 706, this suggests a significant break in a potential pattern.

4. Determine the incorrect number

It appears based on the previous calculations the number after 1402 should maintain a consistent pattern.

Check if 1402 was generated by some operation. Instead, identify if one of the other numbers deviates.

5. Finalize the conclusion

After evaluating the differences and potential relationships, it seems that the number following 1402 should not be as low as 706 in the context of the other values.