SOLUTION: The monthly salary of Mr.Gill is the same each month. In November, Mr Gill spent $1600 of his month salary And saved the rest. In December, he increased his Spending by 30% and

Let x be his saving in November (exactly the unknown value).


Then his saving in December was 0.5x, according to the condition.


Thus his November salary is 1600 + x dollars;

     his December salary is 1600*1.3 + 0.5x  dollars.


The salary is the same -- it gives you an equation


    1600 + x = 2080 + 0.5x


Simplify and solve it :


    x - 0.5x = 2080 - 1600

    0.5x     = 480

    x =  = 960.


ANSWER.  His November saving was 960 dollars.

He increased his spending by 1600*0.3 = 480 dollars, and, therefore (or due to it), he decreased his saving in half.


Hence, half of his saving in November is exactly 480 dollars -- thus his saving on November was 2*480 = 960 dollars.


You get the same result.