•  Given that x is greater than or equal to 25. Also, y is less than or equal to 40.

•  Let’s try to find the various values of y – x.

•  If y = 40, x can take various values like 25, 26, 27,...

•  In that case y – x will take values like 15, 14, 13, 12,......0, - 1 etc.

•  If y = 39, x can take various values 25, 26, 27,...

•  In that case y – x will take values like 14, 13, 12, 11 ..... 0, - 1 etc.

•  Similarly, if y = 38, values of y – x will be 13, 12, 11, ..... 0, -1 etc. and so on.

•  So, we can say that value of y – x is less than or equal to 15 in all cases.