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| 1 | +--- |
| 2 | +title: IIT M FOUNDATION ET1 EXAM QPF1 S2 30 |
| 3 | +weight: 1 |
| 4 | +label: Apr 2023 |
| 5 | +categories: |
| 6 | +- PYQ |
| 7 | +--- |
| 8 | + |
| 9 | +--- |
| 10 | + |
| 11 | +## Mathematics for Data Science |
| 12 | + |
| 13 | +### 1. How many edges are there in a graph with 10 vertices each of degree 6? |
| 14 | + |
| 15 | +**Solution:** |
| 16 | +In any graph, the sum of degrees of all vertices is twice the number of edges. |
| 17 | +Sum of degrees = 10 × 6 = 60 |
| 18 | +So, number of edges = 60 / 2 = **30**[^1]. |
| 19 | + |
| 20 | +### 2. What is the minimum number of colours required to colour the given graph? |
| 21 | + |
| 22 | +**Solution:** |
| 23 | +The answer given is **3**. This is a typical graph colouring problem, where the chromatic number is 3[^1]. |
| 24 | + |
| 25 | +### 3. What is the weight of a minimum cost spanning tree of the given graph? |
| 26 | + |
| 27 | +**Solution:** |
| 28 | +The answer is **23**. (This is a direct answer, as the graph is not provided here.)[^1] |
| 29 | + |
| 30 | +### 4. How many critical points of \$ f(x, y) \$ are there? |
| 31 | + |
| 32 | +**Solution:** |
| 33 | +The answer is **9**. Critical points are where the gradient is zero[^1]. |
| 34 | + |
| 35 | +### 5. The function \$ f(x) = x^3 - 12x \$ has a: |
| 36 | + |
| 37 | +- Local maximum at \$ x = -2 \$ |
| 38 | +- Local minimum at \$ x = 2 \$ |
| 39 | + |
| 40 | +**Explanation:** |
| 41 | +Find critical points by setting \$ f'(x) = 0 \$: |
| 42 | +\$ f'(x) = 3x^2 - 12 = 0 \implies x^2 = 4 \implies x = -2, 2 \$ |
| 43 | +Second derivative: \$ f''(x) = 6x \$ |
| 44 | +At \$ x = -2 \$, \$ f''(-2) = -12 < 0 \$ ⇒ local maximum |
| 45 | +At \$ x = 2 \$, \$ f''(2) = 12 > 0 \$ ⇒ local minimum[^1]. |
| 46 | + |
| 47 | +### 6. Let \$ f \$ be differentiable at \$ x = 2 \$. The tangent at \$ (2, 6) \$ passes through \$ (6, -18) \$. What is \$ f'(2) \$? |
| 48 | + |
| 49 | +**Solution:** |
| 50 | +Slope of the tangent = \$ \frac{-18 - 6}{6 - 2} = \frac{-24}{4} = -6 \$ |
| 51 | +So, \$ f'(2) = -6 \$[^1]. |
| 52 | + |
| 53 | +### 7. What is the minimum sum of three non-negative numbers whose product is 27? |
| 54 | + |
| 55 | +**Solution:** |
| 56 | +Let the numbers be \$ a, b, c \geq 0 \$, \$ abc = 27 \$. |
| 57 | +By AM-GM inequality, minimum sum occurs when \$ a = b = c \$. |
| 58 | +So, \$ a = b = c = 3 \$, sum = \$ 3 + 3 + 3 = 9 \$[^1]. |
| 59 | + |
| 60 | +### 8. What is the value of \$ f'(2) \$ if the tangent at \$ (2, 6) \$ passes through \$ (6, -18) \$? |
| 61 | + |
| 62 | +**Solution:** |
| 63 | +Already solved above: **-6**[^1]. |
| 64 | + |
| 65 | +## Statistics for Data Science |
| 66 | + |
| 67 | +### 9. Sushant throws a die, then throws as many coins as the number on the die. If the die shows 5, what is the probability of getting exactly 3 heads? |
| 68 | + |
| 69 | +**Solution:** |
| 70 | +Number of coins = 5. |
| 71 | +Probability of 3 heads = \$ \binom{5}{3} \times (0.5)^3 \times (0.5)^2 = 10 \times 0.125 \times 0.25 = 0.3125 \$ |
| 72 | +So, the answer is approximately **0.313**[^1]. |
| 73 | + |
| 74 | +### 10. Expected number of people shortlisted if for every 5 interviewed, 1 is selected, and 20 people are interviewed? |
| 75 | + |
| 76 | +**Solution:** |
| 77 | +Expected = \$ 20 \times \frac{1}{5} = 4 \$[^1]. |
| 78 | + |
| 79 | +### 11. Suppose the lifetime of a radio is uniformly distributed between 100 to 120 weeks. What is the probability it lasts more than 115 weeks given it has already worked for 110 weeks? |
| 80 | + |
| 81 | +**Solution:** |
| 82 | +Conditional probability = \$ \frac{120 - 115}{120 - 110} = \frac{5}{10} = 0.5 \$[^1]. |
| 83 | + |
| 84 | +### 12. The number of customers arriving each day at a petrol pump is Poisson with mean 10. What is the probability that on a particular day, more than 3 customers arrive? |
| 85 | + |
| 86 | +**Solution:** |
| 87 | +Probability = \$ 1 - P(at most 3) \$. For Poisson(10), \$ P(X \leq 3) \$ is very small, so \$ P(X > 3) \approx 1 \$. The answer is in the range **0.96 to 1**[^1]. |
| 88 | + |
| 89 | +### 13. Find the total numbers greater than 6000 that can be formed using the digits 0, 2, 3, 6, 9 without repetition. |
| 90 | + |
| 91 | +**Solution:** |
| 92 | +Numbers must be 4 or 5 digits, starting with 6 or 9. |
| 93 | +For 4-digit: |
| 94 | +First digit: 6 or 9 (2 choices), then choose 3 from 4 digits: \$ 4 \times 3 \times 2 = 24 \$ for each, total 48. |
| 95 | +For 5-digit: All digits used, first digit can't be 0, so 4 choices (2, 3, 6, 9), but only 6 and 9 are >6000, so 2 choices, total \$ 4! = 24 \$ each, so 48. |
| 96 | +Total = 48 + 96 = **144**[^1]. |
| 97 | + |
| 98 | +## Introduction to Python |
| 99 | + |
| 100 | +### 14. Which of the following code blocks prints the product of the digits for a given number? |
| 101 | + |
| 102 | +**Solution:** |
| 103 | +The correct code block should: |
| 104 | + |
| 105 | +- Initialize a variable (e.g., `prod = 1`) |
| 106 | +- Loop through each digit of the number (using `while n > 0`) |
| 107 | +- Multiply `prod` by `n % 10` |
| 108 | +- Update `n = n // 10` |
| 109 | +- Print `prod` at the end[^1]. |
| 110 | + |
| 111 | + |
| 112 | +## English |
| 113 | + |
| 114 | +### 15. Convert the following sentence into passive voice: |
| 115 | + |
| 116 | +"Inder stores grapes in this room." |
| 117 | +**Solution:** |
| 118 | +"Grapes are stored in this room by Inder."[^1] |
| 119 | + |
| 120 | +### 16. Choose the most grammatically correct sentence. |
| 121 | + |
| 122 | +**Solution:** |
| 123 | +"Yesterday was quite an alarming day."[^1] |
| 124 | + |
| 125 | +### 17. What is the meaning of 'isolation'? |
| 126 | + |
| 127 | +**Solution:** |
| 128 | +"The process or state of being lonely or alone."[^1] |
| 129 | + |
| 130 | +### 18. What is the antonym of the word 'common'? |
| 131 | + |
| 132 | +**Solution:** |
| 133 | +"Rare"[^1] |
| 134 | + |
| 135 | +## Computational Thinking |
| 136 | + |
| 137 | +### 19. In a dictionary D, which statement is true? |
| 138 | + |
| 139 | +**Solution:** |
| 140 | + |
| 141 | +- `keys(D)` is a list of distinct elements. |
| 142 | +- Value of a key in D can be another dictionary[^1]. |
| 143 | + |
| 144 | + |
| 145 | +### 20. If a procedure returns a list of names of customers who have visited shop B, and each customer must be represented exactly once, what is a possible mistake? |
| 146 | + |
| 147 | +**Solution:** |
| 148 | + |
| 149 | +- Incorrect initialization of the set/list to store unique names. |
| 150 | +- Incorrect update condition. |
| 151 | +- Incorrect update statement[^1]. |
| 152 | + |
| 153 | +**Note:** |
| 154 | + |
| 155 | +- For many questions, the original exam refers to diagrams, code, or data not included here. Where possible, the answer is explained or the formula used is shown. |
| 156 | +- For MCQs with only options and no context, only the correct answer is provided as per the answer key. |
| 157 | + |
| 158 | +[^1]: All answers and explanations are based on the extracted content from the provided IIT-M Foundation exam document. |
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