2016 - JAMB Mathematics Past Questions and Answers - page 4
31
The mean of 2-t, 4+t, 3-2t, 2+t and t-1 is
A
2
B
t
C
-t
D
-2
correct option: a
Mean = \(\frac{2 - t + 4 + t + 3 - 2t + 2 + t + t - 1}{5}\)
= \(\frac{10}{5}\) = 2
Users' Answers & Comments= \(\frac{10}{5}\) = 2
32
Evaluate \(\frac{12.02 \times 20.06}{26.04 \times 60.06}\), correct to three significant figures.
A
0.157
B
0.154
C
0.155
D
0.158
correct option: b
\(\frac{12.02 \times 20.06}{26.04 \times 60.06}\) = \(\frac{241.1212}{15698.96}\) = 0.154
Users' Answers & Comments33
If y = 2x3 + 6x2 + 6x + 1, Find \(\frac{dy}{dx}\)
A
6x2 + 12x + 1
B
6x2 + 6x + 1
C
6x2 + 6x + 6
D
6x2 + 12x + 6
34
The nth term of the sequence 3, 9, 27, 81.....is
A
3 x 3n-2
B
3 x 3n-1
C
3 x 3n+2
D
3 x 3n+1
correct option: b
3,9,27,81,.....
r = \(\frac{9}{8}\) = 3
Tn = arn-1
Tn = 3(3)n-1 = \(\frac{3(3^2)}{3}\)
Users' Answers & Commentsr = \(\frac{9}{8}\) = 3
Tn = arn-1
Tn = 3(3)n-1 = \(\frac{3(3^2)}{3}\)
35
Simplify 1 - (\(\frac{1}{7}\) x 3 \(\frac{1}{2}\)) \(\div\) \(\frac{3}{4}\)
A
2
B
\(\frac{1}{3}\)
C
1
D
\(\frac{2}{3}\)
correct option: b
1 - (\(\frac{1}{7}\) x 3 \(\frac{1}{2}\)) \(\div\) \(\frac{3}{4}\)
1 - (\(\frac{1}{7}\) x \(\frac{7}{2}\)) x \(\frac{4}{3}\)
1 - \(\frac{1}{2}\) x \(\frac{4}{3}\)
1 - \(\frac{2}{3}\) = \(\frac{1}{3}\)
Users' Answers & Comments1 - (\(\frac{1}{7}\) x \(\frac{7}{2}\)) x \(\frac{4}{3}\)
1 - \(\frac{1}{2}\) x \(\frac{4}{3}\)
1 - \(\frac{2}{3}\) = \(\frac{1}{3}\)
36
If a car travels 120km on 45 litres of petrol, how much petrol is needed for a journey of 600km?
A
720 litres
B
160 litres
C
225 litres
D
960 litres
correct option: c
120km \(\to\) 45litres
1km \(\to\) \(\frac{45}{120}\)litres
600km \(\to\) \(\frac{45}{120}\) x 600 = 225litres
Users' Answers & Comments1km \(\to\) \(\frac{45}{120}\)litres
600km \(\to\) \(\frac{45}{120}\) x 600 = 225litres
37
Find \(\frac{dy}{dx}\). If y = 3x3 + 2x2 + 3x + 1
A
9x2 + 4x + 3
B
9x2 - 4x - 3
C
9x2 + 4x - 3
D
9x2 - 4x + 3
38
Evaluate \(\int\)(sinx - 5x2)dx
A
-cosx - 10x + k
B
cosx - \(\frac{5x^3}{3}\) + k
C
-cosx - \(\frac{5x^3}{3}\) + k
D
cosx - 10x + k
39
If N = \(\frac{p}{2}\)(\(\frac{T_1 - T_2}{T_1}\)). Find P when N = 12, T1 = 27 and T2 = 24.
A
48
B
108
C
54
D
216
correct option: d
N = \(\frac{p}{2}\)(\(\frac{T_1 - T_2}{T_1}\))
12 = \(\frac{p}{2}\)(\(\frac{27 - 24}{27}\))
24 = P(\(frac{3}{27}\)
P = 24 x 9 = 216
Users' Answers & Comments12 = \(\frac{p}{2}\)(\(\frac{27 - 24}{27}\))
24 = P(\(frac{3}{27}\)
P = 24 x 9 = 216
40
Solve for x and y respectively
3x - 5y = 9
6x - 4y = 12
3x - 5y = 9
6x - 4y = 12
A
\(\frac{3}{4}\), 1
B
\(\frac{4}{3}\), 1
C
\(\frac{3}{4}\), -1
D
\(\frac{4}{3}\), -1
correct option: d
3x - 5y = 9 ------x2
6x - 4y = 12 -----x1
6x - 10y = 18
-6x - 4y = 12
____________
\(\frac{6y}{-6}\) = \(\frac{6}{6}\)
y = -1
in eq (1) 3x - 5y = 9
3x - 5(-1) = 9
3x + 5 = 9
3x = 4
x = \(\frac{4}{3}\)
Users' Answers & Comments6x - 4y = 12 -----x1
6x - 10y = 18
-6x - 4y = 12
____________
\(\frac{6y}{-6}\) = \(\frac{6}{6}\)
y = -1
in eq (1) 3x - 5y = 9
3x - 5(-1) = 9
3x + 5 = 9
3x = 4
x = \(\frac{4}{3}\)