Find the wrong number in the following number series:

4, 5.1, 7.3, 10.6, 15, 20, 27.1

Question

Find the wrong number in the following number series:

4, 5.1, 7.3, 10.6, 15, 20, 27.1

Accepted Answer

**Solution:**

1. Observe the series: 4, 5.1, 7.3, 10.6, 15, 20, 27.1

2. Calculate the differences between consecutive terms:
   - 5.1 - 4 = 1.1
   - 7.3 - 5.1 = 2.2
   - 10.6 - 7.3 = 3.3
   - 15 - 10.6 = 4.4
   - 20 - 15 = 5
   - 27.1 - 20 = 7.1

3. The pattern in differences should increase by 1.1 each time:
   - 1.1, 2.2, 3.3, 4.4, 5.5, 6.6

4. The difference between 15 and 20 is 5, which breaks the pattern. It should be 5.5 instead of 5.

5. Therefore, the correct number after 15 should be:
   $$15 + 5.5 = 20.5$$

6. Since the series has 20 instead of 20.5, the wrong number is **20**.

**Answer:** 20

Answer

Answer

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