Fill suitable number in the blank

To find the missing number in the pie chart sequence, let's observe the pattern:

1. The first pie chart has sections: 5, 6, and the total as 15.
2. The second pie chart has sections: 6, 7, and the total as 21.
3. The third pie chart has sections: 7, 10, and the total we need to find.

First, notice how the totals relate to the sections:

- First pie chart: \(5 + 6 + 4 = 15\)
- Second pie chart: \(6 + 7 + 8 = 21\)

The sum of the numbers in the first two charts increases by 6 (from 15 to 21).

Now for the third pie chart:

- For the third pie chart, we have \(7 + 10 + ?\).

To calculate:

If we maintain the same increase pattern (from 15 to 21 is an increase of 6), the next total should be:

\( 21 + 6 = 27 \).

Now we can find the missing section:

\[
7 + 10 + ? = 27
\]
\[
17 + ? = 27
\]
\[
? = 27 - 17
\]
\[
? = 10
\]

Thus, the missing number is **10**.