Simplify (x - 3y)2 - (x + 3y)2
2(x + 3y)
(2x - 3y)
-12xy
6xy
Correct answer is C
(x - 3y)2 - (x + 3y)2 = [(x - 3y) - (x + 3y)]
[(x + 3y + x + 3y)] = [-6y] [2x]
= -12xy
it is a scalene triangle
it is right angled isosceles triangle
it is an equilateral triangle
It is an isosceles triangle but not right angled
Correct answer is C
(x + 10)o + (2x - 40)o + (3x - 90)o = 180
6x - 120 = 180
6x = 180 + 120
6x = 300
x = \(\frac{300}{6}\)
x = 50
x + 10o = 50o + 10o = 60o
2x - 40 = 2(50o) - 40 = 60o
3x - 90 = 3(50o) - 90o = 60o
Hence, it is an equilateral triangle
Simplify; \(\frac{1}{2}\sqrt{32} - \sqrt{18} \sqrt{2}\)
zero
\(\sqrt{2}\)
2\(\sqrt{2}\)
4\(\sqrt{2}\0
Correct answer is A
\(\frac{1}{2}\sqrt{32} - \sqrt{18} \sqrt{2}\) = \(\frac{1}{2} (4\sqrt{2}) - 3\sqrt{2} + \sqrt{2}\)
= 2\(\sqrt{2} - 3\sqrt{2} + \sqrt{2}\)
= 3\(\sqrt{2} - 3\sqrt{2} - 3\sqrt{2}\) = 0
3
7
9
12
Correct answer is C
Total no of balls = 30
Let x = no. of red balls
Pr(red) = \(\frac{x}{30}\)
Pr(black) = \(\frac{3}{10} = \frac{9}{30}\)
Pr(white) = \(\frac{2}{5} = \frac{12}{30}\)
No. of black balls = 9
No. of white balls = 12
9 = 12 + x = 30
x = 30 - 21
x = 9
No. of red balls = 9
28
280
2800
28000
Correct answer is D
No. of buckets of water = \(\frac{\text{Capacity of reservoir}}{\text{Capacity of buckets}}\)
= \(\frac{800 \times 700 \times 500}{10 \times 1000}\)
= \(\frac{28000 0000}{10000}\)
= 28000