Question
If a sum when placed at compound interest grows to
Rs.6,400 in 2 yrs and to Rs. 8,000 in 3 yrs, find the rate percent p.a.Solution
Let the principal be P. ∴ P + CI for 3 yrs = Rs. 8,000----- (i) And P + CI for 2 yrs = Rs. 6,400----- (ii) Subtracting (ii) from (i), we get CI for the 3rd yr = 8,000 – 6,400 = Rs. 1600 Thus, CI calculated in the 3rd yr is basically the interest on the amount generated after 2 yrs which is Rs. 6,400. R = (SI × 100)/(P × T) = (1600 × 100)/(6400 × 1) = 25 % p.a.
I. p2 – 15p + 56 = 0
II. q2 + 2q – 63 = 0
I. x² + 11x + 24 = 0
II. y² + 17y + 72 = 0
I. 2 x ² + x  – 1 = 0                Â
II. 2 y ² - 3 y + 1 = 0
...(i) 2x² – 9x + 10 = 0
(ii) 4y² – 12y + 9 = 0
I. 5x2 – 7x – 6 =0
II. 2y2 – 5y – 7 =0
Solve the quadratic equations and determine the relation between x and y:
Equation 1: x² - 29x + 210 = 0
Equation 2: y² - 27y + 182 = 0
I. 8y2 - 2y - 21 = 0
II. 2x2 + x - 6 = 0
I. x2 + 25x + 154 = 0
II. y2 + 27y + 181 = 0
I. 6y2 – 23y + 20 = 0
II. 4x2 – 24 x + 35 = 0
I. 18p²- 21p + 6 = 0   Â
II. 16q² - 24q +9 = 0
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