Solved papers class 11 Maths CBSE ALL INDIA 2022 – 2023

📝 SECTION E

Case Study Based · 3 × 4 = 12 marks

Q36.
🏘️ Village Highway Case Study

Villages of Shanu and Arun are 50km apart on Delhi-Agra highway. Another highway YY’ crosses at O(0,0). A local road PQ crosses both highways at A and B such that OA = 10 km and OB = 12 km. Barun’s village B is 12km from O and Jeetu’s village is 15km from O on YY’.

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Answer the following questions based on the above information:

(a) What are the coordinates of A?

(i) (10,0)
(ii) (10,12)
(iii) (0,10)
(iv) (0,15)

(b) What is the equation of line AB?

(i) 5x + 6y = 60
(ii) 6x + 5y = 60
(iii) x = 10
(iv) y = 12

(c) What is the distance of AB from O(0,0)?

(i) 60 km
(ii) \(\frac{60}{\sqrt{61}}\) km
(iii) \(\sqrt{61}\) km
(iv) 60 km

(d) What is the slope of line AB?

(i) \(\frac{6}{5}\)
(ii) \(\frac{5}{6}\)
(iii) \(-\frac{6}{5}\)
(iv) None of these
🔍 VIEW SOLUTIONS

✅ STEP-BY-STEP SOLUTIONS:

(a) Coordinates of A:

From the description, OA = 10 km on Delhi-Agra highway. Since Delhi-Agra highway is along x-axis (as O is at origin and highways cross at O), point A lies on x-axis at distance 10 from O.

Therefore, coordinates of A = (10, 0).

✅ Answer: (i) (10,0)

(b) Equation of line AB:

Point A = (10, 0), Point B = (0, 12) (since OB = 12 km on YY’ which is y-axis).

Equation of line through two points: \(\frac{y – y_1}{y_2 – y_1} = \frac{x – x_1}{x_2 – x_1}\)

\(\frac{y – 0}{12 – 0} = \frac{x – 10}{0 – 10}\)

\(\frac{y}{12} = \frac{x – 10}{-10}\)

Cross multiply: \(-10y = 12(x – 10)\)

\(-10y = 12x – 120\)

\(12x + 10y = 120\)

Divide by 2: \(6x + 5y = 60\)

✅ Answer: (ii) 6x + 5y = 60

(c) Distance of AB from O(0,0):

Distance from point to line formula: \(d = \frac{|Ax_0 + By_0 + C|}{\sqrt{A^2 + B^2}}\)

Line AB: \(6x + 5y – 60 = 0\) (from part b)

Point O(0,0): \(d = \frac{|6(0) + 5(0) – 60|}{\sqrt{6^2 + 5^2}} = \frac{|-60|}{\sqrt{36 + 25}} = \frac{60}{\sqrt{61}}\)

✅ Answer: (ii) \(\frac{60}{\sqrt{61}}\) km

(d) Slope of line AB:

Slope \(m = \frac{y_2 – y_1}{x_2 – x_1} = \frac{12 – 0}{0 – 10} = \frac{12}{-10} = -\frac{6}{5}\)

✅ Answer: (iii) \(-\frac{6}{5}\)

✅ Q36 Answers: (a) (10,0) (b) 6x+5y=60 (c) \(\frac{60}{\sqrt{61}}\) km (d) \(-\frac{6}{5}\)

Q37.
🎲 Probability Case Study

Two students Anil and Ashima appeared in an examination. The probability that Anil qualifies is 0.05, Ashima qualifies is 0.10, and both qualify is 0.02.

Based on the given information, answer the following:

(a) The probability that Ashima will not qualify the examination:

(i) 0.9
(ii) 0.5
(iii) 0.8
(iv) 0.2

(b) The probability that at least one of them will qualify:

(i) 0.09
(ii) 0.13
(iii) 0.25
(iv) 0.19

(c) Probability that at least one of them will not qualify:

(i) 0.82
(ii) 0.74
(iii) 0.56
(iv) 0.98

(d) The probability that both will not qualify:

(i) 0.43
(ii) 0.67
(iii) 0.87
(iv) 0.91
🔍 VIEW SOLUTIONS

✅ STEP-BY-STEP PROBABILITY CALCULATIONS:

Given:

P(Anil qualifies) = P(A) = 0.05

P(Ashima qualifies) = P(S) = 0.10

P(both qualify) = P(A ∩ S) = 0.02

(a) P(Ashima does not qualify):

P(S’) = 1 – P(S) = 1 – 0.10 = 0.9

✅ Answer: (i) 0.9

(b) P(at least one qualifies) = P(A ∪ S):

P(A ∪ S) = P(A) + P(S) – P(A ∩ S)

= 0.05 + 0.10 – 0.02 = 0.13

✅ Answer: (ii) 0.13

(c) P(at least one does not qualify):

This is complement of P(both qualify):

P(at least one does not qualify) = 1 – P(both qualify)

= 1 – 0.02 = 0.98

✅ Answer: (iv) 0.98

(d) P(both do not qualify):

P(both do not qualify) = P(A’ ∩ S’) = 1 – P(A ∪ S) [De Morgan’s Law]

= 1 – 0.13 = 0.87

Alternatively: P(A’ ∩ S’) = 1 – P(A ∪ S) = 1 – 0.13 = 0.87

✅ Answer: (iii) 0.87

✅ Q37 Answers: (a) 0.9 (b) 0.13 (c) 0.98 (d) 0.87

Q38.
🃏 Cards Combinations

Two friends Ajay and Rahul are playing cards. Ajay asks Rahul to choose any four cards from a pack of 52.

Answer the following questions based on above information:

(a) In how many ways can Rahul select all 4 cards from heart cards?

(i) 2680
(ii) 2086
(iii) 715
(iv) 517

(b) In how many ways can he select all 4 cards from different suits?

(i) 28561
(ii) 26581
(iii) 25861
(iv) None of these

(c) In how many ways can he select all face cards?

(i) 505
(ii) 485
(iii) 495
(iv) None of these

(d) In how many ways can he select 2 red and 2 black cards?

(i) 106525
(ii) 105525
(iii) 105265
(iv) None of these
🔍 VIEW SOLUTIONS

✅ STEP-BY-STEP COMBINATIONS:

Note: Total cards = 52. 4 suits: Hearts (13), Diamonds (13), Clubs (13), Spades (13). Red = Hearts + Diamonds (26), Black = Clubs + Spades (26). Face cards: Jack, Queen, King of each suit (12 total).

 

(a) All 4 cards from hearts:

Number of heart cards = 13,

Ways to choose 4 from 13

= C(13,4) \(= \frac{13 \times 12 \times 11 \times 10}{4 \times 3 \times 2 \times 1} = \frac{17160}{24} = 715\)

✅ Answer: (iii) 715

(b) All 4 cards from different suits:

We need one card from each of the 4 suits.

Number of ways = \(C(13,1) \times C(13,1) \times C(13,1)\)\( \times C(13,1) = 13^4 = 28561\)

✅ Answer: (i) 28561

(c) All face cards:

Total face cards = 4 suits × 3 face cards (J, Q, K) = 12

Ways to choose 4 from 12 = \(C(12,4) = \frac{12 \times 11 \times 10 \times 9}{4 \times 3 \times 2 \times 1} = \frac{11880}{24} = 495\)

✅ Answer: (iii) 495

(d) 2 red and 2 black cards:

Choose 2 red from 26 red cards: \(C(26,2) = \frac{26 \times 25}{2} = 325\)

Choose 2 black from 26 black cards: \(C(26,2) = 325\)

Total ways = \(325 \times 325 = 105625\)

Check given options: 106525, 105525, 105265, none of these.

105625 is not listed, so correct is “None of these”.

✅ Answer: (iv) None of these

✅ Q38 Answers: (a) 715 (b) 28561 (c) 495 (d) None of these (correct value 105625)