Express 0.0462 in standard form
0.460 x 10-1
0.462 x 10-2
4.62 x 10-1
4.62 x 10-2
Correct answer is D
No explanation has been provided for this answer.
If N varies directly as M and N = 8 when M = 20 find M when N = 7
13
15
\(17\frac{1}{2}\)
\(18\frac{1}{2}\)
Correct answer is C
N ∝ M
∴N = kM where k is a constant
N = 8 when M = 20
∴ 8 = k x 20
\(k = \frac{8}{20} = \frac{2}{5}\\
∴ N = \frac{2}{5}M\\
If N = 7\\
∴ 7 = \frac{2}{5}M\\
M = \frac{35}{2} = 17\frac{1}{2}\)
15
30
35
45
Correct answer is C
Let c = no of students that offered both subjects ∴ No of students offering Economics = 65 - c No of students offering Geography = 50 - c 65 - c + c + 50 - c = 80 115 - c = 80 c = 35 35 students offer both Economics and Geography.
Evaluate \(log_{10}5 + log_{10}20\)
2
3
4
5
Correct answer is A
\(log_{10}5 + log_{10}20\\
log_{10}[5\times 20]\\
log_{10}100\\
log_{10}10^2\\
2log_{10}10=2\)
Evaluate \((20_{three})^2 - (11_{three})^2\) in base three
101
121
202
2020
Correct answer is C
\((20_{three})^2 - (11_{three})^2\)
= \((20_{3} - 11_{3})(20_{3} + 11_{3})\)
= \((2_{3})(101_{3})\)
= \(202_{3}\)