How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.
60
62
54
64
Correct answer is B
T2 = 4, T4 = 16
Tx = arn-1
T2 = ar2-1 = 4 i.e. ar3 = 16, i.e. ar = 4
T4 = ar4-1
therefore, \(\frac{T_4}{T_r}\) = \(\frac{ar^3}{ar}\) = \(\frac{16}{4}\)
r2 = 4 and r = 2
but ar = 4
a = \(\frac{4}{r}\) = \(\frac{4}{2}\)
a = 2
Sn = \(\frac{a(r^n - 1)}{r - 1}\)
S5 = \(\frac{2(2^5 - 1)}{2 - 1}\)
= \(\frac{2(32 - 1)}{2 - 1}\)
= 2(31)
= 62
Find the sum of the first 18 terms of the series 3, 6, 9,..., 36.
505
513
433
635
Correct answer is B
3, 6, 9,..., 36.
a = 3, d = 3, i = 36, n = 18
Sn = \(\frac{n}{2}\) [2a + (n - 1)d
S18 = \(\frac{18}{2}\) [2 x 3 + (18 - 1)3]
= 9[6 + (17 x 3)]
= 9 [6 + 51] = 9(57)
= 513
Solve the inequality x2 + 2x > 15.
x < -3 or x > 5
-5 < x < 3
x < 3 or x > 5
x > 3 or x < -5
Correct answer is B
x2 + 2x > 15
x2 + 2x - 15 > 0
(x2 + 5x) - (3x - 15) > 0
x(x + 5) - 3(x + 5) >0
(x - 3)(x + 5) > 0
therefore, x = 3 or -5
i.e. x< 3 or x > -5
Solve the inequality -6(x + 3) \(\leq\) 4(x - 2)
x \(\leq\) 2
x \(\geq\) -1
x \(\geq\) -2
x \(\leq\) -1
Correct answer is B
-6(x + 3) \(\leq\) 4(x - 2)
-6(x +3) \(\leq\) 4(x - 2)
-6x -18 \(\leq\) 4x - 8
-18 + 8 \(\leq\) 4x +6x
-10 \(\leq\) 10x
10x \(\geq\) -10
x \(\geq\) -1
T varies inversely as the cube of R. When R = 3, T = \(\frac{2}{81}\), find T when R = 2
\(\frac{1}{18}\)
\(\frac{1}{12}\)
\(\frac{1}{24}\)
\(\frac{1}{6}\)
Correct answer is B
T \(\alpha \frac{1}{R^3}\)
T = \(\frac{k}{R^3}\)
k = TR3
= \(\frac{2}{81}\) x 33
= \(\frac{2}{81}\) x 27
dividing 81 by 27
k = \(\frac{2}{2}\)
therefore, T = \(\frac{2}{3}\) x \(\frac{1}{R^3}\)
When R = 2
T = \(\frac{2}{3}\) x \(\frac{1}{2^3}\) = \(\frac{2}{3}\) x \(\frac{1}{8}\)
= \(\frac{1}{12}\)