DRDO Multi tasking staff Model paper 1

Let Rs. x part be lent at 8% simple interest
⇒ Rs. (20000 - x) Part is lent at 8/3 % simple interest.
Now, as per given total simple interest after an year = Rs. 800
⇒

x×8×1

100

+

(20000−x)× 8 3 ×1

100

=800
⇒ (24x + 160000 - 8x)/300 = 800
⇒ 16x + 160000 = 240000
⇒ 16x = 80000
⇒ x = 80000/16 = Rs. 5000
∴ the sum lent at 8/3 % = (20000 - 5000) = Rs. 15000