The following bar graph shows the total number of newspaper readers (in thousands) in a city during 6 consecutive months in a particular year and the respective percentages of the above-mentioned readers who read Hindi newspapers.
The rest of the readers read English newspapers.

Note: Total readers = Hindi newspaper readers + English newspaper readers

What is the difference between the number of Hindi newspaper readers during January, February and April taken together and that of English newspaper readers during March, May and June taken together?

The difference between the number of Hindi newspaper readers during January, February and April taken together and that of English newspaper readers during March, May and June taken together = [(140 of 65% + 150 of 70% + 90 of 75%) - (130 of (100-40)%+110 of (100-50)%+80 of (100-80)%)] $$\times1000$$

= [(140 of 65% + 150 of 70% + 90 of 75%) - (130 of 60%+110 of 50%+80 of 20%)] $$\times1000$$

= $$[(140\times\frac{65}{100}+150\times\frac{70}{100}+90\times\frac{75}{100})-(130\times\frac{60}{100}+110\times\frac{50}{100}+80\times\frac{20}{100})]$$ $$\times1000$$