Evaluate \(5\frac{2}{5}\times \left(\frac{2}{3}\right)^2\div\left(1\frac{1}{2}\right)^{-1}\)
\(\frac{8}{25}\)
\(\frac{12}{25}\)
\(3\frac{3}{5}\)
\(4\frac{1}{8}\)
Correct answer is C
\(5\frac{2}{5}\times \left(\frac{2}{3}\right)^2 ÷ \left(1\frac{1}{2}\right)^{-1}\\
\frac{27}{5}\times \frac{4}{9} \times \frac{3}{2}=3\frac{3}{5}
\)
95%
47.5%
5.26%
5%
Correct answer is D
The percentage error is \(\frac{error}{actual}\times \frac{100}{1}\%\\
=\frac{200-190}{200}\times \frac{100}{1}\\
=\frac{10}{200}\times \frac{100}{1}\% = 5\%\)
81
72
54
45
Correct answer is A
Ratio of good ones to bad ones is 5:4; If 36 is bad;
∴ the good ones = \(\frac{5\times 36}{4}=45\) oranges.
The total number of oranges is 36 + 45 = 81.
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.