Question
R' invested some money at a compound interest rate of
40% p.a., compounded quarterly. If after 9 months, he received an amount of Rs. 1,99,650, then the sum invested by 'R' is equal to: I. The interest received when Rs. 1,25,000 is invested at S.I of 30% p.a. for 4 years. II. The C.P of an item sold for Rs. 2,40,000 at a profit of 40%. III. The difference between the savings of 'Pawan' and 'Qureshi', whose incomes are Rs. (a + 406320) and Rs. (a + 156320), given that each spends 40% of their respective incomes.Solution
ATQ, Effective rate of interest = 40 ÷ 4 = 10% p.a. And effective time period = (9/12) × 4 = 3 terms We know that for compound interest, Amount = Sum × {1 + (rate of interest/100)} time period Let the sum invested be Rs. 'S' So, 199650 = S X {1 + (10/100)} ³ Or, 199650 = S X (1.1) ³ Or, 199650 = 1.331S So, S = 1,50,000 Therefore, sum invested = Rs. 1,50,000 For I: Interest received = (125000 × 0.3 × 4) = Rs. 1,50,000 Therefore, statement I is true. For II: CP of the item = (240000/1.4) = Rs. 171428.57 Therefore, statement II is false. For III: Difference between savings of 'Pawan' and 'Qureshi' = 0.6 × (a + 406320) - 0.6 × (a + 156320) = 0.6 × (406320 - 156320) = 0.6 × 250000 = Rs. 1,50,000 Therefore, statement III is true.
If α, β are the roots of the equation x² – px + q = 0, then the value of α2+β2+2αβ isÂ
...I. 8x² - 74x + 165 = 0
II. 15y² - 38y + 24 = 0
I. x2 - x - 56 = 0
II. y2 - 20y + 96 = 0
I. p² - 10p +21 = 0
II. q² + q -12 = 0
I. 2x2 – 10x – 48 = 0
II. y2 – 16y – 297 = 0
 If x satisfies x² – 14x + 40 = 0, find x.
I. x2 – 18x + 81 = 0
II. y2 – 3y - 28 = 0
I. 2y² - 35y + 132 = 0
II. 2x² - 31x + 110 = 0
I. 25p + 2(2p2 – 1) = 8(p + 5)
II. 8q2 + 35q – 78 = 0
I. 88x² - 13 x – 56 = 0
II. 15 y² + 41 y + 28 = 0