Question

A man had rupees 4000, part of which he lent at 5% and the rest at 4% . the whole interest received was rupees 190. how much did he Lent at 4%? solution​

Answer 1

Let Rs x lent at 5% interest and Rs y at 4% interest.

Total money had Rs 4000

Therefore,  x + y = 4000     -----------(1)

Interest on Rs x = 5% of x

                          = 0.05x

Interest on Rs y = 4% of y

                          = 0.04x

Total interest received = Rs 190

0.05x + 0.04y = 190   -----------------(2)

using eq(1) and eq(2) solve for x and y

By elimination method, multiply first equation by -0.04

-0.04x -0.04y = -160

0.05x + 0.04y = 190

               0.01x = 30

                      x = 3000

Put x into x + y = 4000

3000 + y = 4000

             y = 1000

Hence, Rs 1000 lent at 4%