A. 10, 3
B. -10, 3
C. -20, 3
D. -10, -3
Sum of the roots and the product of the roots are -20 and 3 respectively.
A. x2 + 13x – 140 = 0
B. x2 – 13x + 140 = 0
C. x2 – 13x – 140 = 0
D. x2 + 13x + 140 = 0
Explanation:
Any quadratic equation is of the form
x2 – (sum of the roots)x + (product of the roots) = 0 —- (1)
where x is a real variable. As sum of the roots is 13 and product of the roots is -140, the quadratic equation with roots as 20 and -7 is: x2 – 13x – 140 = 0.
If the roots of a quadratic equation are 20 and -7, then find the equation? Read More »
Mathematics Mcqs, Quadratic Equations A. rational and unequal
B. complex
C. real and equal
D. irrational and unequal
Explanation:
The discriminant of the quadratic equation is (-12)2 – 4(3)(10) i.e., 24. As this is positive but not a perfect square, the roots are irrational and unequal.
The roots of the equation 3×2 – 12x + 10 = 0 are? Read More »
Mathematics Mcqs, Quadratic Equations A. 3, -3/2
B. 3/2, -3
C. -3/2, -3
D. 3/2, 3
Explanation:
2×2 + 6x – 3x – 9 = 0
2x(x + 3) – 3(x + 3) = 0
(x + 3)(2x – 3) = 0
=> x = -3 or x = 3/2.
Find the roots of the quadratic equation: 2×2 + 3x – 9 = 0? Read More »
Mathematics Mcqs, Quadratic Equations A. -5, 3
B. 3, 5
C. -3, 5
D. -3, -5
Explanation:
x2 + 5x – 3x – 15 = 0
x(x + 5) – 3(x + 5) = 0
(x – 3)(x + 5) = 0
=> x = 3 or x = -5.
Find the roots of the quadratic equation: x2 + 2x – 15 = 0? Read More »
Mathematics Mcqs, Quadratic Equations A. 4 : 3
B. 8 : 7
C. 4 : 1
D. 6 : 5
Let the length and breadth of the carpet in the first case be 3x units and 2x units respectively.
Let the dimensions of the carpet in the second case be 7y, 3y units respectively.
From the data,.
2(3x + 2x) = 2(7y + 3y)
=> 5x = 10y
=> x = 2y
Required ratio of the areas of the carpet in both the cases
= 3x * 2x : 7y : 3y
= 6×2 : 21y2
= 6 * (2y)2 : 21y2
= 6 * 4y2 : 21y2
= 8 : 7
A. 91.5 cm
B. 93.5 cm
C. 94.5 cm
D. 92.5 cm
Perimeter of the sector = length of the arc + 2(radius)
= (135/360 * 2 * 22/7 * 21) + 2(21)
= 49.5 + 42 = 91.5 cm
The sector of a circle has radius of 21 cm and central angle 135o. Find its perimeter? Read More »
Mathematics Mcqs, Mensuration A. 140
B. 156
C. 175
D. 214
Given that the area of the square = 1225 sq.units
=> Side of square = √1225 = 35 units
The radius of the circle = side of the square = 35 units Length of the rectangle = 2/5 * 35 = 14 units
Given that breadth = 10 units
Area of the rectangle = lb = 14 * 10 = 140 sq.units
A. 225 sq.m
B. 360 sq.m
C. 600 sq.m
D. 480 sq.m
Find the area of a rhombus whose side is 25 cm and one of the diagonals is 30 cm? Read More »
Mathematics Mcqs, Mensuration A. 81 : 121
B. 9 : 11
C. 729 : 1331
D. 27 : 12
Ratio of the sides = ³√729 : ³√1331 = 9 : 11
Ratio of surface areas = 92 : 112 = 81 : 121
