Find the roots of the quadratic equation: 2×2 + 3x – 9 = 0?
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.
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.
A. 1 cm
B. 2 cm
C. 4 cm
D. 3 cm
A. 9, 10
B. 10, 11
C. 11, 12
D. 12, 13
Explanation:
Let the two consecutive positive integers be x and x + 1
x2 + (x + 1)2 – x(x + 1) = 91
x2 + x – 90 = 0
(x + 10)(x – 9) = 0 => x = -10 or 9.
As x is positive x = 9
Hence the two consecutive positive integers are 9 and 10.
A. 25%
B. 50%
C. 20%
D. 5%
E. None of these
Explanation:
L.C.M of 15 and 12 = 60
CP of 60 articles = Rs. 100 (25 * 4)
SP of 60 articles = Rs. 150 (30 * 5)
Profit percentage = (150 – 100)/100 * 100 = 50%
A. 10 kmph
B. 21 kmph
C. 8 kmph
D. 12 kmph
Explanation:
S = 4
M = x
DS = x + 4
US = x – 4
6/(x + 4) + 6/(x – 4) = 2
x = 8
Origin lies on the intersection of the x-axis and y-axis, i.e, (0,0).
A. 14.4 minutes
B. 20 minutes
C. 28.8 minutes
D. 32 minutes
(2/3)*24=16 miles Time taken to cover the first 16 miles
= (16/40) hours
= 24 minutes Time taken to cover the next 8 miles
= (8/60) hours
= 8 minutes Time taken for the entire journey
= 32 minutes