The value of for which the equation has real and equal roots, is:
- (A)
- (B)−4
- (C)
- (D)−2
The official board paper (Q.P. Code 30/5/1, Series 5LMKN). Free paper PDF and step-by-step solutions (also as a PDF to download) written by CogniGuru and checked against CBSE’s answer key. See the paper’s main topics in 1 minute, then quiz yourself to see how much you know and where you stand.
No login to download or read the solutions. Login only to see your quiz report in full.
Three pages of the official paper. Download the PDF for all 24.
Your tutor walks you through the paper before you attempt it: the marks, the key ideas, the time plan and the traps.
1-minute paper analysis
With your tutor, in her voice
A short, animated walk through the paper: how it is built, where the marks come from, the four ideas that matter most, how to plan your three hours, and the traps to avoid.
Sound on for the voice. Captions are shown, and you can mute any time.
Try each question first, then open its solution. Tap a number to jump.
20 questions, 1 mark each. MCQs (Q1 to Q18) and assertion-reason (Q19, Q20).
The value of for which the equation has real and equal roots, is:
The line segment joining the points and is divided by -axis in the ratio:
Answer: (A) 2 : 5
Report an error on this questionIf the zeroes of a polynomial are and , then equals:
Answer: (B)
Report an error on this questionIn the given figure, is tangent to the circle with centre . is a point on the circle such that . The is:

Answer: (B)
Report an error on this questionDevansh proved that using SAS similarity criteria. If he found , then which of the following was proved true?
Answer: (D)
Report an error on this questionWhile calculating mean of a grouped frequency distribution, step deviation method was used . It was found that , and . The value of is:
A conical cavity of maximum volume is carved out from a wooden solid hemisphere of radius cm. Curved surface area of the cavity carved out is (use ):

Answer: (A) cm²
Report an error on this questionIf represents term of the A.P. , then value of is:
The value of for which roots of the quadratic equation are rational, is:
Answer: (B) −5
Report an error on this questionWhich of the following can not be the probability of an event?
Answer: (C)
Report an error on this questionA card is drawn at random from a well shuffled deck of 52 playing cards. The probability that it is either a ten or a king is:
A camping tent in hemispherical shape of radius m, has a door opening of area m². Outer surface area of the tent is:
Answer: (C) 11.82 m²
Report an error on this questionAn arc of length cm subtends an angle at the centre of the circle with radius cm. The value of is:
For an acute angle , if , then value of is:
In the given figure, such that . If cm, then equals:

Meena calculates that the probability of her winning the first prize in a lottery is 0.08. If total 800 tickets were sold, the number of tickets bought by her is:
A wire is attached from a point on the ground to the top of a pole , making an angle of elevation as . If m, then length of the wire is:

Simplest form of is:
Assertion (A): The system of linear equations and is inconsistent.
Reason (R): When two linear equations don’t have unique solution, they always represent parallel lines.
Answer: (C) A is true, but R is false
Report an error on this questionAssertion (A): H.C.F. , where is a prime number.
Reason (R): H.C.F. of two numbers is always less than or equal to the smaller number.
Answer: (B) Both A and R are true, but R is not the correct explanation of A
Report an error on this question5 questions, 2 marks each.
Prove that is an irrational number given that is irrational.
Answer: Proved
Report an error on this question(a) Vertices of a right triangle with are , and . Find the value of .
OR
(b) Using distance formula, prove that the points , and are collinear.
Answer: (a) (b) collinear
Report an error on this questionIn the given figure, and . Show that . If cm, cm and cm, then find the length .

Answer: cm
Report an error on this question(a) Evaluate:
OR
(b) For acute angles and , and are acute if and , then find the measures of angles and .
Answer: (a) (b) ,
Report an error on this questionA bag contains 25 balls. Some of them are yellow and others are green. One ball is drawn at random. If probability of getting a green ball is 3/5, then find the number of yellow balls.
6 questions, 3 marks each.
A circle of diameter 20 cm is equally divided into five sectors. Find the area and perimeter of one of the sectors.
Answer: Area cm²; perimeter cm
Report an error on this question(a) In an A.P., term exceeds the term by . If sum of first terms is , then form the A.P.
OR
(b) The sum of first terms of an A.P. is . Find its term and hence term.
Answer: (a) (b) ,
Report an error on this questionProve that: .
(a) A circle centered at passes through the points and . Find the value(s) of . Hence find length of chord .
OR
(b) Prove that the point dividing the line segment joining the points and in the ratio , lies on the line . Also find length of and .
Answer: (a) () or () (b) on the line, ,
Report an error on this questionSolve the system of linear equations: and graphically.
Answer: ,
Report an error on this questionThe dimensions of a window are cm cm. Arjun wants to put grill on the window creating complete squares of maximum size. Determine the side length of the square and hence find the number of squares formed.
Answer: Side cm; squares
Report an error on this question4 questions, 5 marks each.
Venkat can row a boat in still water at the speed of 12 km/h. He ferries tourists 15 km upstream and 18 km downstream in 3 hours. Find the speed of the stream.
Answer: km/h
Report an error on this question(a) is the mid-point of side of . and intersect at , a point on . is produced to such that . Prove that (i) is a parallelogram (ii) (iii) .
OR
(b) Through the mid-point of side of a parallelogram , the line is drawn which intersects at and produced at . Prove that (i) (ii) (iii) .

Answer: Proved (both parts)
Report an error on this question(a) The mean of the following frequency distribution is . If sum of all frequencies is , then find the values of and :
OR
(b) Find median and mode of the following distribution (classes with frequencies ).
| Class Interval | 0–10 | 10–20 | 20–30 | 30–40 | 40–50 | 50–60 |
|---|---|---|---|---|---|---|
| Frequency | 12 | p | 27 | 20 | q | 6 |
Answer: (a) , (b) median , mode
Report an error on this questionand are two tangents to a circle with centre and radius cm. is another tangent to the circle at which lies on . If cm, then find the length and .

Answer: cm, cm
Report an error on this question3 case studies, 4 marks each.
Case study 1. An arch of a railway bridge, built on Chenab riverbed, is shown in the above diagram. It is a parabolic arch connecting two hills at P and Q. If the parabolic curve is represented by the polynomial p(x) = −0.0025x² − 0.025x + 136.
Observe the diagram and based on above information, answer the following questions:
(i) Write the co-ordinates of point A. [1]
(ii) Find the span of the arch. [1]
(iii) (a) Write the zeroes of the polynomial using diagram and verify the relationship between sum of zeroes and polynomials. [2]
OR
(iii) (b) Find the values of p(x) at x = 100 and x = −100. Are they same? [2]

Answer: (i) (ii) units (iii)(a) zeroes and , sum (iii)(b) and , not the same
Report an error on this questionCase study 2. A wall mounted lamp, made of fabric, is shown below. Lamp has cuboidal shape, open from top and bottom. A spherical bulb of diameter 7 cm is latched with a very thin rod. (Ignore the rod while making calculations.) Dimensions of the cuboid are 24 cm × 12 cm × 17 cm.
Based on the above information, answer the following questions:
(i) Find the surface area of the bulb. [1]
(ii) What could be the maximum diameter of the bulb if at least 1 cm space is left from each side? [1]
(iii) (a) Find the area of the fabric used if there is a fold of 2 cm on top and bottom edges. [2]
OR
(iii) (b) Find the space available inside the lamp. [2]

Answer: (i) cm² (ii) cm (iii)(a) cm² (iii)(b) cm³
Report an error on this questionCase study 3. Elevated water storage tanks are built to store and supply water to nearby colonies. In the diagram given above, AB is an elevated water tank and CD is a nearby multistorey building. The building is 54 metres away from the water tank. From a window (W) of the building, the angle of elevation of top of the tank is 45° and angle of depression of its foot is 30°.
Based on the above information, answer the following questions:
(i) Write a relation between d (the height of window) and y. [1]
(ii) Determine the value of h. [1]
(iii) (a) Determine height of the water tank. [2]
OR
(iii) (b) Find the value of x and height of the window above ground level. [2]

Answer: (i) (ii) m (iii)(a) m (iii)(b) m; window height m
Report an error on this questionQuestions are from the official CBSE paper. Figures are described in words; see the PDF for the originals. Solutions are written by CogniGuru.
Each chapter below is what the paper tested, with a one-minute animated lesson on the idea behind it.
Trigonometry
Q14, Q17, Q18, Q24, Q28, Q38 (12 marks): standard values and the identity sin² + cos² = 1.
How to remember trig values at 0°, 30°, 45°, 60°, 90° — Class 10Triangles
Q5, Q15, Q23, Q33 (9 marks): similarity criteria, matching angles by sides, and the Basic Proportionality Theorem.
Why are two equal angles enough to prove triangles similar (AA)? — Class 10Congruence vs Similarity — why equal angles alone prove nothingQuadratic Equations
Q1, Q9, Q32 (7 marks): the discriminant, standard form and solving by factorising.
Why does a quadratic have at most two real roots? — Class 10Coordinate Geometry
Q2, Q22, Q29 (6 marks): the distance, mid-point and section formulas.
Why is the distance formula just Pythagoras? — Class 10Midpoint Formula vs Section Formula — Class 10Circles
Q4, Q35 (6 marks): a tangent is perpendicular to the radius, and tangents from one point are equal.
Why is a tangent perpendicular to the radius? — Class 10Statistics
Q6, Q34 (6 marks): mean, median and mode of grouped data.
Mean vs Median vs Mode — why one outlier can lie to youReal Numbers
Q20, Q21, Q31 (6 marks): HCF and LCM, rational and irrational numbers, and proofs of irrationality.
Rational vs Irrational Numbers — is 22/7 actually equal to π?Why is √2 irrational? The proof — Class 10Polynomials
Q3, Q36 (5 marks): zeroes, their sum and product, and reading zeroes from a graph.
Why is the sum of zeroes −b/a and the product c/a? — Class 10Probability
Q10, Q11, Q16, Q25 (5 marks): favourable outcomes over total outcomes, and sure events.
Why is probability always between 0 and 1? — Class 10Arithmetic Progressions
Q8, Q27 (4 marks): the nth term and the sum of n terms.
Arithmetic vs Geometric Progression — why doubling always wins eventuallyLinear Equations
Q19, Q30 (4 marks): solving a pair of equations, graphing it, and when a pair is consistent.
When do two linear equations have no solution? — Class 10Stuck on a step in any solution?
The CogniGuru AI tutor explains any doubt one minute at a time, in English or Hindi. Join the waitlist.
Five real questions from this paper, one each from five chapters. About 2 minutes. See how much you know and where you stand among other students. Attempt free, with no login; log in only for your ranking and full report.
The line segment joining the points and is divided by -axis in the ratio:
0 of 5 answered