The sum invested in scheme B is thrice the sum invested in scheme A. The investment in scheme A is made for 4 years at 8% p.a. simple interest and in scheme B for 2 years at 13% p.a. simple interest. The total interest earned from both the schemes is Rs. 1320. How much amount was invested in scheme A?

Solution (By Examveda Team)

Let the amount invested in scheme A be Rs. x and that in B be Rs. 3x.
Then,
$$\eqalign{ & = \frac{{x \times 4 \times 8}}{{100}} + \frac{{3x \times 2 \times 13}}{{100}} = 1320 \cr & or,\,\frac{{32x}}{{100}} + \frac{{78x}}{{100}} = 1320 \cr & or,\,\frac{{110x}}{{110}} = 1320 \cr & \therefore x = \frac{{1320 \times 100}}{{110}} \cr & = {\text{Rs}}{\text{. 1200}}. \cr} $$