Following the bar graph shows percentage distribution number of challans generated in five different cities (A,B,C,D and E) in two different months (June and July) . Total number of challans generated in June and July is 800 and 1200 respectively.

If 55% of the total number of challans generated in city B in both the months together are paid offline, find the number of challans paid online in city B in both the month together.

The correct answer is 279.

From the given bar graph and question data, we have the following total values:

- Total number of challans generated in June = 800

- Total number of challans generated in July = 1200

Looking at the bar graph for City B:

- Percentage of challans generated in City B in June (represented by the blue bar) = 25%

- Percentage of challans generated in City B in July (represented by the orange bar) = 35%

Step 1: Calculate the total number of challans generated in City B in June.

$\text{Challans in B (June)}=25\%\text{ of }800=\frac{25}{100}\times 800=200$

Step 2: Calculate the total number of challans generated in City B in July.

$\text{Challans in B (July)}=35\%\text{ of }1200=\frac{35}{100}\times 1200=420$

Step 3: Find the total number of challans generated in City B in both months together.

$\text{Total Challans in B}=200+420=620$

Step 4: Find the number of challans paid online in City B.

It is given that 55% of the total challans in City B were paid offline. Therefore, the percentage of challans paid online is:

$100\%-55\%=45\%$

Now, calculate 45% of 620:

$\text{Number of online challans}=\frac{45}{100}\times 620=0.45\times 620=279$

Thus, the total number of challans paid online in city B in both months together is 279.