Question

Divide 3600 into two parts such that if one part be lent at 9% per annum and the other at 10% per annum the total annual income is 333

Answer 1

let one part be x, then other part is (3600 - x)

Case 1 : SI = (x * 9 * 1) /100

            => SI = 9x/100

Case 2: SI = [(3600-x)*10*1]/100

             => SI = (3600-x)/10

according to problem, 

9x/100  +  (3600-x)/10 = 333

or, (9x + 36000-10x) = 33300

or, -x + 36000 = 33300

or,  x = 36000-33300

or x = 2700

two parts are 2700 and 900