₹ 9800 is invested partly in 9% stock at 75 and 10% stock at 80 to have equal amount of incomes. The investment in 9% stock is:
Rs. 5000
Let the investment in 9% stock be Rs.x .
Then, investment in 10% stock = ₹ (9800 - x).
975×x=1080×(9800−x)⇒3X25=9800−x8⇒24x=9800×25−25x⇒49x=9800×25x=5000.