Find the mean of the numbers 1, 3, 4, 8, 8, 4 and 7
4
5
6
7
Correct answer is B
mean \(=\frac{1+3+4+8+8+4+7}{7}=\frac{35}{7}=5\)
Given that the root of an the equation \(2x^2 + (k+2)x+k=0\) is 2, find the value of k
-4
-2
-1
\(-\frac{1}{4}\)
Correct answer is A
Substituting for x in the equation
\(2(2)^2 + (k+2)2+k = 0 \Rightarrow 8 +2k + 4 + k =0 \Rightarrow 3k =-12; k=-4\)
A sequence is given by \(2\frac{1}{2}, 5, 7\frac{1}{2}, .....\) if the nth term is 25, find n
9
10
12
15
Correct answer is B
\(a = 2\frac{1}{2}, nth = a + (n-1)d \Rightarrow 25 = 2\frac{1}{2} + (n-1)2\frac{1}{2}\\
25 = \frac{5}{2}+(n-1)\frac{5}{2} \Rightarrow 22\frac{1}{2} = \frac{5n-5}{2}\Rightarrow \frac{45}{2} = \frac{5n-5}{2}\\
45 = 5n - 5 \Rightarrow 5n = 50 \Rightarrow n = 10\)
36
27
24.5
13.5
Correct answer is B
\(log_9x= 1.5\Rightarrow x = 9^{1.5} = 9^{\frac{3}{2}}=(3^2)^{\frac{3}{2}}=3^3=27\)
Solve the equation \(\frac{2y-1}{3} - \frac{3y-1}{4} = 1\)
-8
-13
13
19
Correct answer is B
\(\frac{4(2y-1)-3(3y-1)}{12}=12 \Rightarrow 8y - 4 - 9y + 3 = 12 \\
\Rightarrow -y-1=12\Rightarrow -y=13\Rightarrow y=-13\)