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 'a' and the other be '3600-a'
annual income is the simple interest
SI = PTR /100

equation 1,
SI = a*1*9/100
equation 2,
SI = (3600-a)*1*10/100

adding both equations, we have,
annual income = 9a/100 + (3600-a)*10/100
333= (9a + 36000- 10a) /100
33300 = 36000- a
a = 36000- 33300
a= 2700

therefore one part is 2700 and the other is 900 (3600-2700).