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.
The mean of seven numbers is 10. If six of the numbers are 2, 4, 8, 14, 16 and 18, find the mode.
6
8
14
2
Correct answer is B
Using x = \(\frac{\sum x}{N}\) in each case, we get;
\(\sum_{6}^{i=1} x_i\) = 10 x 7 = 70
\(\sum_{7}^{i=1} x_i\) = 2 + 4 + 8 + 14 + 16 + 18 = 62
Hence the missing number can be obtained from
\(\sum_{6}^{i=1} x_i - \sum_{7}^{i=1} x_i\) = 70 - 62 = 8
So, all the seven numbers are 2, 4, 8, 8, 14, 16, 18
Mode = 8
Find the mean of t + 2, 2t - 4, 3t + 2 and 2t.
t + 1
2t
2t + 1
t
Correct answer is B
\(\sum x\) = (t + 2) + (2t + 4) + (3t + 2) + 2t = 8t
N = 4_
∴ Mean, x = \(\frac{\sum x}{N} = \frac{8t}{4} = 2t\)
= 2t
0.75cm2S-1
0.53cm2S-1
0.35cm2S-1
0.88cm2S-1
Correct answer is D
A = \(\pi\)r2, \(\frac{\delta A}{\delta r}\) = 2πr
So, using \(\frac{\delta A}{\delta t}\) = \(\frac {\delta A}{\delta r}\) x \(\frac {\delta A}{\delta t}\)
= 2\(\pi\)r x 0.02
= 2\(\pi\) x 7 x 0.02
= 2 x \(\frac{22}{7}\) x 0.02
= 0.88cm2s-1
If y = (2x + 2)\(^3\), find \(\frac{\delta y}{\delta x}\)
3(2x +2)2
6(2x +2)
3(2x +2)
6(2x +2)2
Correct answer is D
\(y = (2x + 2)^{3}\)
\(\frac{\mathrm d y}{\mathrm d x} = 3(2x + 2)^{3 - 1} . 2\)
= \(6(2x + 2)^{2}\)
If y = x sin x, find \(\frac{\delta y}{\delta x}\)
sin x - cos x
cos x - x sin x
cos x + x sin x
sin x + x cos x
Correct answer is D
y = x sin x
Where u = x and v = sin x
Then \(\frac{\delta u}{\delta x}\) = 1 and \(\frac{\delta v}{\delta x}\) = cos x
By the chain rule, \(\frac{\delta y}{\delta x} = v\frac{\delta u}{\delta x} + u\frac{\delta v}{\delta x}\)
= (sin x)1 + x cos x
= sin x + x cos x