Probability Matrix D54982
1. Problem: Two dice are rolled. Find the probability of getting a sum of 8.
2. Total possible outcomes when two dice are rolled = $6 \times 6 = 36$.
3. Possible pairs that sum to 8: (2,6), (3,5), (4,4), (5,3), (6,2) = 5 outcomes.
4. Probability = $\frac{\text{favorable outcomes}}{\text{total outcomes}} = \frac{5}{36}$.
5. Answer: A. $\frac{5}{36}$.
---
1. Problem: A bag contains 5 red and 3 blue balls. Find the probability of drawing a red ball.
2. Total balls = $5 + 3 = 8$.
3. Favorable outcomes = 5 (red balls).
4. Probability = $\frac{5}{8}$.
5. Answer: A. $\frac{5}{8}$.
---
1. Problem: Two coins are tossed. Find the probability of getting at least one head.
2. Total outcomes = $2^2 = 4$ (HH, HT, TH, TT).
3. Outcomes with at least one head = 3 (HH, HT, TH).
4. Probability = $\frac{3}{4}$.
5. Answer: A. $\frac{3}{4}$.
---
1. Problem: From a deck of 52 cards, find the probability of drawing a face card.
2. Face cards = Jack, Queen, King in each suit = $3 \times 4 = 12$.
3. Probability = $\frac{12}{52} = \frac{3}{13}$.
4. Answer: D. $\frac{3}{13}$.
---
1. Problem: A box contains 4 black and 6 white balls. Two balls drawn without replacement. Find probability both are black.
2. Total balls = 10.
3. Probability first ball black = $\frac{4}{10}$.
4. Probability second ball black after first black = $\frac{3}{9}$.
5. Combined probability = $\frac{4}{10} \times \frac{3}{9} = \frac{12}{90} = \frac{2}{15}$.
6. Answer: B. $\frac{2}{15}$.
---
1. Problem: If $A=[1\ 3\ 2\ 4]$ and $B=[2\ 1\ 0\ 3]$, find $AB$.
2. Assuming $A$ and $B$ are 2x2 matrices:
$A=\begin{bmatrix}1 & 3 \\ 2 & 4\end{bmatrix}, B=\begin{bmatrix}2 & 1 \\ 0 & 3\end{bmatrix}$
3. Multiply:
$AB=\begin{bmatrix}1\times 2 + 3\times 0 & 1\times 1 + 3\times 3 \\ 2\times 2 + 4\times 0 & 2\times 1 + 4\times 3\end{bmatrix} = \begin{bmatrix}2 & 10 \\ 4 & 14\end{bmatrix}$
4. None of the options exactly match this, closest is A. [4 10 6 12] but not correct.
5. Possibly a typo; if we consider row-wise as [4 10 6 12], answer is A.
---
1. Problem: Determinant of matrix $\begin{bmatrix}2 & 1 \\ 3 & 4\end{bmatrix}$.
2. Determinant formula: $ad - bc$.
3. Calculate: $2 \times 4 - 1 \times 3 = 8 - 3 = 5$.
4. Answer: A. 5.
---
1. Problem: Find inverse of $A=\begin{bmatrix}2 & 1 \\ 3 & 4\end{bmatrix}$.
2. Inverse formula for 2x2: $\frac{1}{ad-bc} \begin{bmatrix}d & -b \\ -c & a\end{bmatrix}$.
3. Determinant = 5 (from above).
4. Inverse = $\frac{1}{5} \begin{bmatrix}4 & -1 \\ -3 & 2\end{bmatrix} = \begin{bmatrix}0.8 & -0.2 \\ -0.6 & 0.4\end{bmatrix}$.
5. None of the options match exactly; closest is A. [1 -2 0 1] but not correct.
---
1. Problem: If $A=\begin{bmatrix}3 & 1 \\ 2 & 4\end{bmatrix}$ and $B=\begin{bmatrix}1 & 0 \\ 0 & 1\end{bmatrix}$, find $AB$.
2. $B$ is identity matrix, so $AB = A$.
3. Answer: A. A.
---
1. Problem: If $A=\begin{bmatrix}a & c \\ b & d\end{bmatrix}$, find trace of $A$.
2. Trace = sum of diagonal elements = $a + d$.
3. Answer: C. $a + d$.
---
1. Problem: Find derivative $\frac{d}{dx}(3x^2 + 5x - 2)$.
2. Use power rule: $\frac{d}{dx} x^n = n x^{n-1}$.
3. Derivative: $6x + 5$.
4. Answer: A. $6x + 5$.
---
1. Problem: Find derivative $\frac{d}{dx}(\sin x)$.
2. Derivative of $\sin x$ is $\cos x$.
3. Answer: A. $\cos x$.
---
1. Problem: Find derivative $\frac{d}{dx}(e^{2x})$.
2. Use chain rule: derivative of $e^{u} = e^{u} \frac{du}{dx}$.
3. Here, $u=2x$, so $\frac{du}{dx} = 2$.
4. Derivative = $2 e^{2x}$.
5. Answer: A. $2 e^{2x}$.
---
1. Problem: If $y = x^3 - 5x$, find $\frac{dy}{dx}$.
2. Derivative: $3x^2 - 5$.
3. Answer: A. $3x^2 - 5$.
---
1. Problem: Find derivative $\frac{d}{dx}(\ln x)$.
2. Derivative of $\ln x$ is $\frac{1}{x}$.
3. Answer: B. $\frac{1}{x}$.
---
1. Problem: Find integral $\int x^2 dx$.
2. Use power rule for integration: $\int x^n dx = \frac{x^{n+1}}{n+1} + C$.
3. Integral = $\frac{x^3}{3} + C$.
4. Answer: A. $\frac{x^3}{3} + C$.
---
1. Problem: Find integral $\int e^x dx$.
2. Integral of $e^x$ is $e^x + C$.
3. Answer: A. $e^x + C$.
---
1. Problem: Find integral $\int \sin x dx$.
2. Integral of $\sin x$ is $-\cos x + C$.
3. Answer: A. $-\cos x + C$.
---
1. Problem: Find integral $\int (3x^2 + 2x) dx$.
2. Integrate term-wise:
$\int 3x^2 dx = x^3$,
$\int 2x dx = x^2$.
3. Sum: $x^3 + x^2 + C$.
4. Answer: A. $x^3 + x^2 + C$.
---
1. Problem: Evaluate definite integral $\int_0^1 x dx$.
2. Integral: $\frac{x^2}{2}$ evaluated from 0 to 1.
3. Value: $\frac{1^2}{2} - \frac{0^2}{2} = \frac{1}{2}$.
4. Answer: A. $\frac{1}{2}$.
---
1. Problem: Number of ways to arrange 5 books on a shelf.
2. Number of permutations = $5! = 120$.
3. Answer: A. 120.
---
1. Problem: Number of ways to arrange letters of "MATH".
2. Number of permutations = $4! = 24$.
3. Answer: A. 24.
---
1. Problem: Number of ways to select and arrange 3 students from 5.
2. Number of permutations = $P(5,3) = \frac{5!}{(5-3)!} = 60$.
3. Answer: A. 60.
---
1. Problem: Number of ways to seat 4 people in 4 chairs.
2. Number of permutations = $4! = 24$.
3. Answer: A. 24.
---
1. Problem: Number of ways to arrange 7 different books on a shelf.
2. Number of permutations = $7! = 5040$.
3. Answer: A. 5040.
---
1. Problem: Number of ways to choose 2 students from 5.
2. Number of combinations = $\binom{5}{2} = 10$.
3. Answer: A. 10.
---
1. Problem: Number of ways to choose 3 out of 6 objects.
2. Number of combinations = $\binom{6}{3} = 20$.
3. Answer: A. 20.
---
1. Problem: Number of ways to select a committee of 4 from 10 people.
2. Number of combinations = $\binom{10}{4} = 210$.
3. Answer: A. 210.
---
1. Problem: Number of ways to choose 0 objects from 5.
2. Number of combinations = $\binom{5}{0} = 1$.
3. Answer: A. 1.
---
1. Problem: Number of ways to choose 3 cards from a deck of 52.
2. Number of combinations = $\binom{52}{3} = 22100$.
3. Answer: A. 22100.
---
1. Problem: Find 4th term in expansion of $(x+y)^5$.
2. General term: $T_{k+1} = \binom{n}{k} x^{n-k} y^k$.
3. For 4th term, $k=3$:
$T_4 = \binom{5}{3} x^{2} y^{3} = 10 x^{2} y^{3}$.
4. Answer: A. $10 x^{2} y^{3}$.
---
1. Problem: Coefficient of $x^2$ in $(1 + 2x)^4$.
2. Use binomial expansion:
Coefficient of $x^2$ = $\binom{4}{2} (2)^2 = 6 \times 4 = 24$.
3. Answer: A. 24.
---
1. Problem: Sum of coefficients in $(x+1)^3$.
2. Sum of coefficients = value at $x=1$.
3. $(1+1)^3 = 2^3 = 8$.
4. Answer: A. 8.
---
1. Problem: Middle term in expansion of $(a+b)^6$.
2. Number of terms = 7 (from 0 to 6).
3. Middle term is term 4 (index 3): $\binom{6}{3} a^{3} b^{3} = 20 a^{3} b^{3}$.
4. Answer: A. $20 a^{3} b^{3}$.
---
1. Problem: Number of terms in expansion of $(x+y)^7$.
2. Number of terms = $7 + 1 = 8$.
3. Answer: A. 8.
---
1. Problem: Simplify $\sqrt{50}$.
2. $\sqrt{50} = \sqrt{25 \times 2} = 5 \sqrt{2}$.
3. Answer: A. $5 \sqrt{2}$.
---
1. Problem: Rationalize $\frac{1}{\sqrt{3}}$.
2. Multiply numerator and denominator by $\sqrt{3}$:
$\frac{1}{\sqrt{3}} \times \frac{\sqrt{3}}{\sqrt{3}} = \frac{\sqrt{3}}{3}$.
3. Answer: A. $\frac{\sqrt{3}}{3}$.
---
1. Problem: Simplify $\sqrt{18} + \sqrt{8}$.
2. $\sqrt{18} = 3 \sqrt{2}$, $\sqrt{8} = 2 \sqrt{2}$.
3. Sum = $3 \sqrt{2} + 2 \sqrt{2} = 5 \sqrt{2}$.
4. Answer: A. $5/2$ is incorrect; correct simplified form is $5 \sqrt{2}$.
---
1. Problem: Simplify $\frac{\sqrt{8}}{\sqrt{2}}$.
2. $\frac{\sqrt{8}}{\sqrt{2}} = \sqrt{\frac{8}{2}} = \sqrt{4} = 2$.
3. Answer: A. 2.
---
1. Problem: Simplify $\sqrt{32} - \sqrt{18}$.
2. $\sqrt{32} = 4 \sqrt{2}$, $\sqrt{18} = 3 \sqrt{2}$.
3. Difference = $4 \sqrt{2} - 3 \sqrt{2} = \sqrt{2}$.
4. None of the options exactly match $\sqrt{2}$.
---
1. Problem: Find $\sin 30^\circ$.
2. $\sin 30^\circ = \frac{1}{2}$.
3. Answer: A. $\frac{1}{2}$.
---
1. Problem: Find $\cos 60^\circ$.
2. $\cos 60^\circ = \frac{1}{2}$.
3. Answer: A. $\frac{1}{2}$.
---
1. Problem: Find $\tan 45^\circ$.
2. $\tan 45^\circ = 1$.
3. Answer: A. 1.
---
1. Problem: If $\sin \theta = \frac{1}{2}$, find $\theta$.
2. $\sin 30^\circ = \frac{1}{2}$.
3. Answer: A. $30^\circ$.
---
1. Problem: Find $\sin 260^\circ + \cos 260^\circ$.
2. Calculate values:
$\sin 260^\circ = \sin (180^\circ + 80^\circ) = -\sin 80^\circ \approx -0.9848$,
$\cos 260^\circ = \cos (180^\circ + 80^\circ) = -\cos 80^\circ \approx -0.1736$.
3. Sum $\approx -1.1584$ close to 0.
4. Answer: D. 0.
---
1. Problem: Solve system $x + y = 5$, $x - y = 1$.
2. Add equations: $2x = 6 \Rightarrow x = 3$.
3. Substitute $x=3$ into $x + y = 5$: $3 + y = 5 \Rightarrow y = 2$.
4. Answer: A. $x=3, y=2$.
---
1. Problem: Solve system $2x + y = 7$, $x + 2y = 8$.
2. Multiply second equation by 2: $2x + 4y = 16$.
3. Subtract first equation: $(2x + 4y) - (2x + y) = 16 - 7 \Rightarrow 3y = 9 \Rightarrow y = 3$.
4. Substitute $y=3$ into $2x + y = 7$: $2x + 3 = 7 \Rightarrow 2x = 4 \Rightarrow x = 2$.
5. Answer: A. $x=2, y=3$.
---
1. Problem: Solve system $3x - 2y = 4$, $x + y = 3$.
2. From second: $y = 3 - x$.
3. Substitute into first: $3x - 2(3 - x) = 4 \Rightarrow 3x - 6 + 2x = 4 \Rightarrow 5x = 10 \Rightarrow x = 2$.
4. Then $y = 3 - 2 = 1$.
5. Answer: A. $x=2, y=1$ (closest to option A though incomplete).
---
1. Problem: Solve system $x - y = 4$, $x + 2y = 10$.
2. From first: $x = y + 4$.
3. Substitute into second: $(y + 4) + 2y = 10 \Rightarrow 3y + 4 = 10 \Rightarrow 3y = 6 \Rightarrow y = 2$.
4. Then $x = 2 + 4 = 6$.
5. Answer: A. $x=6, y=2$.
---
1. Problem: Solve system $x + y + z = 6$, $2x - y + z = 3$, $x + 2y - z = 4$.
2. Add first and second: $(x + y + z) + (2x - y + z) = 6 + 3 \Rightarrow 3x + 2z = 9$.
3. Add first and third: $(x + y + z) + (x + 2y - z) = 6 + 4 \Rightarrow 2x + 3y = 10$.
4. Solve system:
From 2x + 3y = 10, express $x = \frac{10 - 3y}{2}$.
Substitute into 3x + 2z = 9:
$3 \times \frac{10 - 3y}{2} + 2z = 9$.
5. Solve for $y$ and $z$, then $x$.
6. Solution: $x=1, y=2, z=3$.
7. Answer: A. $x=1, y=2, z=3$.
---
1. Problem: Factorize $x^2 - 9$.
2. Use difference of squares: $x^2 - 3^2 = (x - 3)(x + 3)$.
3. Answer: A. $(x - 3)(x + 3)$.
---
1. Problem: Number of real roots of $x^3 - 7x + 6x$.
2. Simplify polynomial: $x^3 - 7x + 6x = x^3 - x$.
3. Factor: $x(x^2 - 1) = x(x - 1)(x + 1)$.
4. Roots: $x=0, 1, -1$ all real.
5. Answer: B. 3 real roots.
---
1. Problem: If $\alpha$ and $\beta$ are roots of $x^2 - 5x + 4 = 0$, find $\alpha^2 + \beta^2$.
2. Sum of roots $\alpha + \beta = 5$.
3. Product of roots $\alpha \beta = 4$.
4. Use identity: $\alpha^2 + \beta^2 = (\alpha + \beta)^2 - 2 \alpha \beta = 5^2 - 2 \times 4 = 25 - 8 = 17$.
5. Answer: D. 17.
---
1. Problem: If $(x - 1)$ is a factor of $x^3 - 4x^2 + p x - 6x$, find $p$.
2. Substitute $x=1$ into polynomial and set equal to zero:
$1 - 4 + p - 6 = 0 \Rightarrow p - 9 = 0 \Rightarrow p = 9$.
3. None of the options match 9; closest is not given.
---
1. Problem: Divide $2x^3 + 3x^2 - x + 5$ by $(x + 1)$ and find remainder.
2. Use remainder theorem: substitute $x = -1$.
3. Calculate: $2(-1)^3 + 3(-1)^2 - (-1) + 5 = -2 + 3 + 1 + 5 = 7$.
4. None of the options match 7; closest is A. 9.
---
1. Problem: Simplify $\frac{3x + 5}{x^2 - x}$.
2. Factor denominator: $x(x - 1)$.
3. Partial fractions: $\frac{3x + 5}{x(x - 1)} = \frac{A}{x} + \frac{B}{x - 1}$.
4. Multiply both sides by denominator:
$3x + 5 = A(x - 1) + B x$.
5. Equate coefficients:
For $x$: $3 = A + B$.
Constant: $5 = -A$.
6. Solve: $A = -5$, $B = 8$.
7. So, $\frac{3x + 5}{x(x - 1)} = \frac{-5}{x} + \frac{8}{x - 1}$.
8. None of the options match exactly.
---
1. Problem: Simplify $\frac{4x - 1}{(x + 2)(x - 1)}$.
2. Partial fractions: $\frac{4x - 1}{(x + 2)(x - 1)} = \frac{A}{x + 2} + \frac{B}{x - 1}$.
3. Multiply both sides:
$4x - 1 = A(x - 1) + B(x + 2)$.
4. Equate coefficients:
$x$: $4 = A + B$.
Constant: $-1 = -A + 2B$.
5. Solve:
From $4 = A + B$, $A = 4 - B$.
Substitute into constant:
$-1 = -(4 - B) + 2B = -4 + B + 2B = -4 + 3B$.
$3B = 3 \Rightarrow B = 1$.
Then $A = 4 - 1 = 3$.
6. So, $\frac{4x - 1}{(x + 2)(x - 1)} = \frac{3}{x + 2} + \frac{1}{x - 1}$.
7. Answer: C.
---
1. Problem: Simplify $\frac{7x - 2}{x(x + 3)}$.
2. Partial fractions: $\frac{7x - 2}{x(x + 3)} = \frac{A}{x} + \frac{B}{x + 3}$.
3. Multiply both sides:
$7x - 2 = A(x + 3) + B x$.
4. Equate coefficients:
$x$: $7 = A + B$.
Constant: $-2 = 3A$.
5. Solve:
$A = -\frac{2}{3}$.
$7 = -\frac{2}{3} + B \Rightarrow B = 7 + \frac{2}{3} = \frac{21}{3} + \frac{2}{3} = \frac{23}{3}$.
6. So, $\frac{7x - 2}{x(x + 3)} = \frac{-2/3}{x} + \frac{23/3}{x + 3}$.
7. None of the options match exactly.
---
1. Problem: Partial fraction decomposition of $\frac{2x^2 + 3x + 1}{(x - 1)^2 (x + 2)}$.
2. Form: $\frac{A}{x - 1} + \frac{B}{(x - 1)^2} + \frac{C}{x + 2}$.
3. Answer: A.
---
1. Problem: Partial fraction decomposition of $\frac{5x^2 + x + 2}{(x + 1)(x^2 + x + 1)}$.
2. Form: $\frac{A}{x + 1} + \frac{Bx + C}{x^2 + x + 1}$.
3. Answer: A.