CBSE CLASS X MATHEMATICS
MODEL QUESTION PAPER - 1
| Class: X | Academic Session: 2026-27 |
| Subject: Mathematics (Standard / Basic) | Time Allowed: 1.5 Hours |
| Coverage: Chapters 1 to 9 | Max. Marks: 40 |
(a) The sum of the 4th and 8th terms of an A.P. is 24 and the sum of the 6th and 10th terms is 44. Find the first three terms of the A.P.
(b) Solve for x: 1 / (x + 4) − 1 / (x − 7) = 11 / 30, where x ≠ −4, 7.
A group of students of Class X visited a lighthouse near a coast for an educational survey. From the top of a 75 m high lighthouse from the sea level, a student observes two ships approaching it from the same direction. The angles of depression of the two ships are observed to be 30° and 45° respectively.
(a) Draw a labeled geometric diagram representing the given situation. [1]
(b) Find the distance of the nearer ship from the foot of the lighthouse. [1]
(c) Calculate the exact distance between the two ships. (Take √3 = 1.732) [3]
| Q. No. | Correct Answer | Q. No. | Correct Answer |
|---|---|---|---|
| Q1 | (B) xy2 | Q6 | (A) 2.1 cm |
| Q2 | (B) −10 | Q7 | (C) 10 units |
| Q3 | (D) no solution | Q8 | (A) √2 − 1 |
| Q4 | (A) ±0.2 | Q9 | (A) 10√3 m |
| Q5 | (B) 22 | Q10 | (B) −1 |
| Q. No. | Answer | Q. No. | Answer |
|---|---|---|---|
| Q11 | Two numbers | Q16 | 1 |
| Q12 | 0 (Zero) | Q17 | 30° |
| Q13 | a + (n − 1)d | Q18 | 15/4 |
| Q14 | Equilateral | Q19 | 3 |
| Q15 | (0, y) | Q20 | 2√(a2 + b2) |
Q21: Let 5 − √3 = r (rational). Then √3 = 5 − r. Since r is rational, 5 − r is rational, making √3 rational, which contradicts the fact that √3 is irrational. Hence, 5 − √3 is irrational. (2 marks)
Q22: 6x2 − 7x − 3 = 0 ⇒ (2x − 3)(3x + 1) = 0. Zeroes are x = 3/2 and x = −1/3. Sum of zeroes = 3/2 − 1/3 = 7/6 = −b/a; Product = (3/2)(−1/3) = −1/2 = c/a. (2 marks)
Q23: Here a = 21, d = 18 − 21 = −3. an = −81 ⇒ 21 + (n − 1)(−3) = −81 ⇒ (n − 1)(−3) = −102 ⇒ n − 1 = 34 ⇒ n = 35. So, 35th term is −81. (2 marks)
Q24: Let ratio be k : 1. Point on y-axis has x-coordinate = 0. Using section formula: x = [k(−1) + 1(5)] / (k + 1) = 0 ⇒ −k + 5 = 0 ⇒ k = 5. Ratio is 5 : 1. (2 marks)
Q25: LHS = (1/cos A + sin A/cos A)(1 − sin A) = [(1 + sin A)/cos A](1 − sin A) = (1 − sin2 A)/cos A = cos2 A / cos A = cos A = RHS. Hence proved. (2 marks)
SECTION D: Long Answer & Case Study (5 Marks Each)Q26:
(a) a4 + a8 = 24 ⇒ 2a + 10d = 24 ⇒ a + 5d = 12. Also, a6 + a10 = 44 ⇒ 2a + 14d = 44 ⇒ a + 7d = 22. Subtracting gives 2d = 10 ⇒ d = 5, a = −13. First three terms are −13, −8, −3. (2.5 marks)
(b) [(x − 7) − (x + 4)] / [(x + 4)(x − 7)] = 11/30 ⇒ −11 / (x2 − 3x − 28) = 11/30 ⇒ x2 − 3x − 28 = −30 ⇒ x2 − 3x + 2 = 0 ⇒ (x − 1)(x − 2) = 0 ⇒ x = 1 or x = 2. (2.5 marks)
Q27:
(a) Right triangle ABD with height AB = 75 m, ship C at 45° angle (∠ACB = 45°), ship D at 30° angle (∠ADB = 30°). (1 mark)
(b) In ΔABC, tan 45° = AB / BC ⇒ 1 = 75 / BC ⇒ BC = 75 m. (1 mark)
(c) In ΔABD, tan 30° = AB / BD ⇒ 1/√3 = 75 / BD ⇒ BD = 75√3 m.
Distance between ships CD = BD − BC = 75√3 − 75 = 75(√3 − 1) = 75(1.732 − 1) = 75 × 0.732 = 54.9 m. (3 marks)
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