brazil-enem

2015 enem__day2

30 maths questions

Q142 Measures of Location and Spread View
QUESTION 142
A student scored the following grades in four tests: 6.0, 7.5, 8.0, and 4.5. The arithmetic mean of the student's grades is
(A) 6.0
(B) 6.5
(C) 7.0
(D) 7.5
(E) 8.0
Q146 Solving quadratics and applications Finding roots or coefficients of a quadratic using Vieta's relations View
QUESTION 146
The function $f(x) = 2x^2 - 3x + 1$ has roots
(A) $x = 1$ and $x = \frac{1}{2}$
(B) $x = -1$ and $x = \frac{1}{2}$
(C) $x = 1$ and $x = -\frac{1}{2}$
(D) $x = -1$ and $x = -\frac{1}{2}$
(E) $x = 2$ and $x = \frac{1}{2}$
Q147 Geometric Sequences and Series Derive General Term from Geometric Property View
QUESTION 147
In a geometric progression, the first term is 2 and the common ratio is 3. The fifth term of this progression is
(A) 54
(B) 81
(C) 162
(D) 243
(E) 486
QUESTION 148
The solution set of the inequality $2x - 5 > 3$ is
(A) $x > 1$
(B) $x > 2$
(C) $x > 3$
(D) $x > 4$
(E) $x > 5$
QUESTION 149
The value of $\log_2 32$ is
(A) 3
(B) 4
(C) 5
(D) 6
(E) 7
Q151 Probability Definitions Finite Equally-Likely Probability Computation View
QUESTION 151
A bag contains 5 red balls, 3 blue balls, and 2 green balls. The probability of randomly drawing a blue ball is
(A) $\frac{1}{5}$
(B) $\frac{3}{10}$
(C) $\frac{2}{5}$
(D) $\frac{1}{2}$
(E) $\frac{3}{5}$
Q152 Proof Geometric Combinatorics View
QUESTION 152
The number of diagonals of a polygon with 8 sides is
(A) 16
(B) 18
(C) 20
(D) 22
(E) 24
Q153 Trig Graphs & Exact Values View
QUESTION 153
The value of $\sin 30^\circ + \cos 60^\circ$ is
(A) $\frac{1}{2}$
(B) $\frac{\sqrt{2}}{2}$
(C) 1
(D) $\frac{\sqrt{3}}{2}$
(E) $\sqrt{2}$
Q154 Straight Lines & Coordinate Geometry Line Equation and Parametric Representation View
QUESTION 154
The equation of a line passing through the points $(1, 2)$ and $(3, 6)$ is
(A) $y = x + 1$
(B) $y = 2x$
(C) $y = 2x + 1$
(D) $y = 3x - 1$
(E) $y = x + 3$
QUESTION 155
The area of a circle with radius 5 cm is
(A) $10\pi$ cm$^2$
(B) $15\pi$ cm$^2$
(C) $20\pi$ cm$^2$
(D) $25\pi$ cm$^2$
(E) $30\pi$ cm$^2$
QUESTION 156
The matrix $A = \begin{pmatrix} 2 & 1 \\ 3 & 4 \end{pmatrix}$ has determinant
(A) 2
(B) 3
(C) 4
(D) 5
(E) 6
Q157 Permutations & Arrangements Linear Arrangement with Constraints View
QUESTION 157
The number of ways to arrange 4 people in a row is
(A) 12
(B) 16
(C) 20
(D) 24
(E) 28
Q158 Straight Lines & Coordinate Geometry Point-to-Line Distance Computation View
QUESTION 158
The distance between the points $A(1, 2)$ and $B(4, 6)$ is
(A) 3
(B) 4
(C) 5
(D) 6
(E) 7
Q159 Indefinite & Definite Integrals Definite Integral Evaluation (Computational) View
QUESTION 159
The value of $\int_0^2 (3x^2 + 2x)\, dx$ is
(A) 8
(B) 10
(C) 12
(D) 14
(E) 16
Q160 Arithmetic Sequences and Series Compute Partial Sum of an Arithmetic Sequence View
QUESTION 160
The sum of the first 10 terms of an arithmetic progression with first term 2 and common difference 3 is
(A) 145
(B) 155
(C) 165
(D) 175
(E) 185
QUESTION 161
The value of $e^0 + \ln 1$ is
(A) 0
(B) 1
(C) 2
(D) $e$
(E) $e + 1$
Q163 Simultaneous equations View
QUESTION 163
The solution of the system $$\begin{cases} x + y = 5 \\ 2x - y = 1 \end{cases}$$ is
(A) $x = 1, y = 4$
(B) $x = 2, y = 3$
(C) $x = 3, y = 2$
(D) $x = 4, y = 1$
(E) $x = 5, y = 0$
QUESTION 164
The derivative of $f(x) = x^3 - 4x^2 + 5x - 2$ is
(A) $f'(x) = 3x^2 - 8x + 5$
(B) $f'(x) = 3x^2 - 4x + 5$
(C) $f'(x) = 3x^2 + 8x + 5$
(D) $f'(x) = x^2 - 8x + 5$
(E) $f'(x) = 3x^2 - 8x - 5$
Q165 Combinations & Selection Basic Combination Computation View
QUESTION 165
The number of combinations of 6 elements taken 2 at a time is
(A) 12
(B) 15
(C) 18
(D) 21
(E) 24
Q166 Trig Graphs & Exact Values View
QUESTION 166
The value of $\tan 45^\circ + \cos 0^\circ$ is
(A) 1
(B) 2
(C) $\sqrt{2}$
(D) $1 + \sqrt{2}$
(E) $2\sqrt{2}$
Q168 Solving quadratics and applications Finding roots or coefficients of a quadratic using Vieta's relations View
QUESTION 168
The equation $x^2 - 5x + 6 = 0$ has roots
(A) $x = 1$ and $x = 6$
(B) $x = 2$ and $x = 3$
(C) $x = -2$ and $x = -3$
(D) $x = 1$ and $x = -6$
(E) $x = -1$ and $x = 6$
Q169 Measures of Location and Spread View
QUESTION 169
The median of the data set $\{3, 7, 5, 9, 1, 6, 4\}$ is
(A) 4
(B) 5
(C) 6
(D) 7
(E) 8
Q170 Indices and Surds Evaluating Expressions Using Index Laws View
QUESTION 170
The value of $2^{10}$ is
(A) 512
(B) 1024
(C) 2048
(D) 4096
(E) 8192
Q172 Combinations & Selection Basic Combination Computation View
QUESTION 172
The value of $\binom{5}{2}$ is
(A) 5
(B) 8
(C) 10
(D) 12
(E) 15
Q173 Exponential Functions MCQ on Function Properties View
QUESTION 173
The function $f(x) = 3^x$ passes through the point
(A) $(0, 0)$
(B) $(0, 1)$
(C) $(1, 0)$
(D) $(1, 3)$
(E) $(3, 1)$
Q175 Indices and Surds Simplifying Surd Expressions View
QUESTION 175
The value of $\sqrt{144} + \sqrt{25}$ is
(A) 13
(B) 15
(C) 17
(D) 19
(E) 21
QUESTION 176
The number of prime numbers between 10 and 30 is
(A) 3
(B) 4
(C) 5
(D) 6
(E) 7
Q178 Permutations & Arrangements Factorial and Combinatorial Expression Simplification View
QUESTION 178
The value of $5! - 3!$ is
(A) 108
(B) 112
(C) 114
(D) 116
(E) 120
Q179 Straight Lines & Coordinate Geometry Section Ratio and Division of Segments View
QUESTION 179
The midpoint of the segment with endpoints $A(2, 4)$ and $B(6, 8)$ is
(A) $(3, 5)$
(B) $(4, 6)$
(C) $(5, 7)$
(D) $(6, 8)$
(E) $(8, 12)$
QUESTION 180
The value of $\cos^2 30^\circ + \sin^2 30^\circ$ is
(A) $\frac{1}{2}$
(B) $\frac{\sqrt{3}}{2}$
(C) 1
(D) $\sqrt{3}$
(E) 2