X and Y have their monthly incomes in the ratio 9 : 7 while their monthly expenditures are in the ratio 5 : 3. If they save ₹16,000 and ₹14,000 monthly, respectively, then the difference in their monthly incomes is:

If all the girls in school B and school C participated in the function, find the ratio between the number of boys in school B and school C who participated in the function.

Which of the following examples represents an inverse proportional relationship (reverse movement)?