The bar shows the total number of students in four schools and it also shows the difference between boys and girls in these schools.

Total girls in A and B together is what percentage of more than that of girls in C.

The correct answer is 55.55%.

From the given bar chart, data is provided for four schools (A, B, C, and D) where:
• The blue bar represents the total number of students, i.e., Boys + Girls.
• The orange bar represents the difference between boys and girls, i.e., Boys - Girls.

To find the total number of girls in any school, we subtract the difference (Boys - Girls) from the total students (Boys + Girls):

$(\text{Boys}+\text{Girls})-(\text{Boys}-\text{Girls})=2\times \text{Girls}$

Therefore, the number of girls in any school is calculated as:

$\text{Girls}=\frac{(\text{Boys}+\text{Girls})-(\text{Boys}-\text{Girls})}{2}$

Step 1: Calculate the number of girls in School A
From the chart for School A:
• Boys + Girls = 72
• Boys - Girls = 48

$\text{Girls in A}=\frac{72-48}{2}=\frac{24}{2}=12$

Step 2: Calculate the number of girls in School B
From the chart for School B:
• Boys + Girls = 60
• Boys - Girls = 28

$\text{Girls in B}=\frac{60-28}{2}=\frac{32}{2}=16$

Step 3: Calculate the total number of girls in School A and School B together

$\text{Total girls in A and B}=12+16=28$

Step 4: Calculate the number of girls in School C
From the chart for School C:
• Boys + Girls = 48
• Boys - Girls = 12

$\text{Girls in C}=\frac{48-12}{2}=\frac{36}{2}=18$

Step 5: Calculate the required percentage
We need to find by what percentage the total number of girls in A and B together (28) is more than that of girls in C (18):

$\text{Percentage More}=\frac{\text{Girls in (A + B)}-\text{Girls in C}}{\text{Girls in C}}\times 100$

Substituting the calculated values:

$\text{Percentage More}=\frac{28-18}{18}\times 100$

$\text{Percentage More}=\frac{10}{18}\times 100=\frac{5}{9}\times 100=55.555...\%\approx 55.55\%$

Hence, total girls in A and B together is 55.55% more than the number of girls in C.