A sum of ₹10000 is invested in three schemes of simple interest. The annual interest rates are respectively, 4%, 6% and 10%. ₹4000 were invested in the first scheme. If the total interest earned after five years is ₹2800, then how much money was invested in the third scheme?
Answer & explanation
Correct answer: option 3
Let Sum invested in 2nd scheme = x
Sum invested in 3rd scheme = ( 6000 - x )
By using formula ,
Simple Interest = \(\frac{Principal ×Rate × Time }{100}\)
\(\frac{4000 ×4 × 5 }{100}\) + \(\frac{x ×6 × 5 }{100}\) +
\(\frac{(6000-x) ×10× 5 }{100}\) = 2800
800 + \(\frac{x × 3 }{10}\) +\(\frac{(6000-x) × 5 }{10}\) = 2800
\(\frac{3x }{10}\) + \(\frac{30000 - 5x }{10}\) = 2000
3x + 30000 - 5x = 20000
-2x = - 10000
x = 5000
Amount invest in 2nd scheme = 5000
So , Amount invested in 3rd scheme = 6000 - 5000 = 1000