3.0cm
3.5cm
4.0cm
4.5cm
Correct answer is B
Using V = \(\frac{3}{1} \pi r^2h\),
so, 38\(\frac{1}{2} = \frac{1}{3} \times \frac{22}{7} \times r^2 \times 3\)
\(\frac{77}{2} = \frac{22}{7} \times r^2\)
r2 = \(\frac{77 \times 7}{2 \times 22}\)
r2 = \(\frac{49}{4}\)
Hence, r = \(\sqrt{\frac{49}{4}}\)
= 3\(\frac{1}{2}\)
x2 - x - 3 = 0
x2 - 3x - 1 = 0
x2 - 3x - 3 = 0
x2 + 3x - 1 = 0
Correct answer is B
Given; y = x2 - x - 2, y = 2x - 1
Using y = y, gives
x2 - x - 2 = 2x - 1
x2 - 3x - 2 + 1 = 0
therefore, x2 - 3x - 1 = 0
Adding 42 to a given positive number gives the same result as squaring the number. Find the number
14
13
7
6
Correct answer is C
Let the given positive number be x
Then 4 + x = x2
0 = x2 - x - 42
or x2 - x - 42 = 0
x2 - 7x + 6x - 42 = 0
x(x - 7) + 6(x - 7) = 0
= (x + 6)(x - 7) = 0
x = -6 or x = 7
Hence, x = 7
If m = 4, n = 9 and r = 16., evaluate \(\frac{m}{n}\) - 1\(\frac{7}{9}\) + \(\frac{n}{r}\)
1\(\frac{5}{16}\)
1\(\frac{1}{16}\)
\(\frac{5}{16}\)
- 1\(\frac{37}{48}\)
Correct answer is D
If m = 4, n = 9, r = 16,
then \(\frac{m}{n}\) - 1\(\frac{7}{9}\) + \(\frac{n}{r}\)
= \(\frac{4}{9}\) - \(\frac{16}{9}\) + \(\frac{9}{16}\)
= \(\frac{64 - 256 + 81}{144}\)
= \(\frac{-111}{144}\)
= - 1\(\frac{37}{48}\)
Find the equation whose roots are \(\frac{3}{4}\) and -4
4x2 - 13x + 12 = 0
4x2 - 13x - 12 = 0
4x2 + 13x - 12 = 0
4x2 + 13x + 12 = 0
Correct answer is C
Let x = \(\frac{3}{4}\) or x = -4
i.e. 4x = 3 or x = -4
(4x - 3)(x + 4) = 0
therefore, 4x2 + 13x - 12 = 0