The LCM of and is:
- (A)960
- (B)240
- (C)60
- (D)15
Solution · answer (A)
- , so divides .
- When one number is a multiple of the other, the LCM is the larger number: . (The HCF is .)
Answer: (A) 960
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20 questions, 1 mark each. MCQs (Q1 to Q18) and assertion-reason (Q19, Q20).
The LCM of and is:
Answer: (A) 960
Report an error on this questionThe natural number 1 is:
Answer: (D) neither prime nor composite
Report an error on this questionFor any natural number , ends with the digit:
Answer: (B) 5
Report an error on this questionThe graph of is given. The number of distinct zeroes of is:

Answer: (C) 2
Common mistake: Counting the peak or counting the touching point twice. Each meeting point counts once, so there are two distinct zeroes.
Report an error on this questionIf and are two zeroes of a polynomial and , then value of is:
If the pair of linear equations and is consistent and dependent, then:
Answer: (D)
Report an error on this questionWhich of the following sequences is **not** an A.P.?
Answer: (D)
Report an error on this questionIn triangles and , and , then is equal to:
Answer: (C)
Report an error on this questionThe distance of the point from -axis is:
Answer: (A) 3a
Report an error on this questionIf , then the value of is:
Answer: (B)
Report an error on this questionIf , then the value of is:
From a point on the ground, which is m away from the foot of a vertical tower, the angle of elevation of the top of the tower is found to be . The height (in metres) of the tower is:
In the given figure, and are tangents to a circle centred at . If , then equals:

In the given figure, and are tangents to a circle centred at . If , then is equal to:

Answer: (B)
Report an error on this questionArea of a segment of a circle of radius and central angle is:
Answer: (C)
Report an error on this questionA hemispherical bowl is made of steel of thickness cm. The outer radius of the bowl is cm. The volume of steel used (in cm³) is:
The mean and median of a frequency distribution are 43 and 43.4 respectively. The mode of the distribution is:
The probability for a randomly selected number out of to be a composite number is:
Answer: (A)
Common mistake: Counting 1 as composite (giving 16) or as prime. It is neither.
Report an error on this questionAssertion (A): The surface area of the cuboid formed by joining two cubes of sides cm each, end-to-end, is cm².
Reason (R): The surface area of a cuboid of dimensions is .
Answer: (C) A is true, R is false
Report an error on this questionAssertion (A): The mean of first natural numbers is .
Reason (R): The sum of first natural numbers is .
Answer: (D) A is false, R is true
Report an error on this question5 questions, 2 marks each.
If are the zeroes of the quadratic polynomial , then find the value of .
(a) In the given figure, . If cm, cm and cm, find the length of .
OR
(b) In the given figure, , and cm. Find the length of .

Answer: (a) cm (b) cm
Report an error on this questionIf the points , , and taken in this order are the vertices of a parallelogram , then find the values of and .
Answer: and
Report an error on this question(a) If , find the value of .
OR
(b) Prove that: .
Answer: (a) (b) proved
Report an error on this questionIn the given figure, is the centre of the circle. and are tangents. Show that the quadrilateral is cyclic.

Answer: Shown
Report an error on this question6 questions, 3 marks each.
Prove that is an irrational number.
Answer: Proved
Report an error on this questionFind the coordinates of the points of trisection of the line segment joining the points and .
Answer: and
Report an error on this question(a) Prove that: .
OR
(b) If and , then prove that .
Answer: Proved (both parts)
Report an error on this question(a) Prove that the lengths of tangents drawn from an external point to a circle are equal.
OR
(b) Two tangents and are drawn to a circle with centre from an external point . Prove that .
Answer: Proved (both parts)
Report an error on this questionFind the area of the sector of a circle of radius cm and of central angle . Also, find the area of the corresponding major sector. (Use )
Answer: Minor sector cm²; major sector cm²
Report an error on this questionTwo dice are thrown at the same time. Determine the probability that the (i) sum of the numbers on the two dice is 5, and (ii) difference of the numbers on the two dice is 3.
Answer: (i) (ii)
Report an error on this question4 questions, 5 marks each.
Aarush bought 2 pencils and 3 chocolates for ₹ 11 and Tanish bought 1 pencil and 2 chocolates for ₹ 7 from the same shop. Represent this situation in the form of a pair of linear equations. Find the price of 1 pencil and 1 chocolate, graphically.
Answer: A pencil costs ₹ and a chocolate costs ₹
Report an error on this question(a) A person on a tour has ₹ for expenses. If he extends his tour for days, he has to cut down his daily expenses by ₹ . Find the original duration of the tour.
OR
(b) The area of a right-angled triangle is cm². If the base of the triangle exceeds the altitude by cm, find all the three dimensions of the triangle.
Answer: (a) days (b) cm, cm and cm
Report an error on this question(a) Prove that if a line is drawn parallel to one side of a triangle to intersect the other two sides in distinct points, then the other two sides are divided in the same ratio.
OR
(b) As shown in the given figure, a girl of height cm is walking away from the base of a lamp post at a speed of m/s. If the lamp is m above the ground, find the length of her shadow after seconds.

Answer: (a) proved (b) the shadow is m long
Report an error on this questionAn SBI health insurance agent found the following data for distribution of ages of 100 policy holders. The health insurance policies are given to persons of age 15 years and onwards, but less than 60 years.
Find the modal age and median age of the policy holders.
| Age (in yrs) | 15–20 | 20–25 | 25–30 | 30–35 | 35–40 | 40–45 | 45–50 | 50–55 | 55–60 |
|---|---|---|---|---|---|---|---|---|---|
| Number of policy holders | 2 | 4 | 18 | 21 | 33 | 11 | 3 | 6 | 2 |
Answer: Modal age years; median age years
Report an error on this question3 case studies, 4 marks each.
Case study 1. Your elder brother wants to buy a car and plans to take a loan from a bank for his car. He repays his total loan of ₹ 1,18,000 by paying every month, starting with the first instalment of ₹ 1,000 and he increases the instalment by ₹ 100 every month.
Based on the information given above, answer the following questions:
(i) Find the amount paid by him in the 30th instalment. [1]
(ii) If the total number of instalments is 40, what is the amount paid in the last instalment? [1]
(iii) (a) What amount does he still have to pay after the 30th instalment? [2]
OR
(iii) (b) Find the ratio of the tenth instalment to the last instalment. [2]
Answer: (i) ₹ (ii) ₹ (iii)(a) ₹ (iii)(b)
Report an error on this questionCase study 2. Tejas is standing at the top of a building and observes a car at an angle of depression of 30° as it approaches the base of the building at a uniform speed. 6 seconds later, the angle of depression increases to 60°, and at that moment, the car is 25 m away from the building.
Based on the information given above, answer the following questions:
(i) What is the height of the building? [1]
(ii) What is the distance between the two positions of the car? [1]
(iii) (a) What would be the total time taken by the car to reach the foot of the building from the starting point? [2]
OR
(iii) (b) What is the distance of the observer from the car when it makes an angle of 60°? [2]

Answer: (i) m (ii) m (iii)(a) s (iii)(b) m
Report an error on this questionCase study 3. On a Sunday your parents took you to a fair. You could see lot of toys displayed and you wanted them to buy a Rubik’s cube and a strawberry ice-cream for you.
Based on the information given above, answer the following questions:
(i) Find the length of the diagonal of Rubik’s cube if each edge measures 6 cm. [1]
(ii) Find the volume of Rubik’s cube if the length of the edge is 7 cm. [1]
(iii) (a) What is the curved surface area of hemisphere (ice-cream) if the base radius is 7 cm? [2]
OR
(iii) (b) If two cubes of edges 4 cm are joined end-to-end, then find the surface area of the resulting cuboid. [2]
Answer: (i) cm (ii) cm³ (iii)(a) cm² (iii)(b) cm²
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
Q10, Q11, Q12, Q24, Q28, Q37 (12 marks): standard values and the identity sin² + cos² = 1.
How to remember trig values at 0°, 30°, 45°, 60°, 90° — Class 10Triangles
Q8, Q22, Q34 (8 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 nothingCircles
Q13, Q14, Q25, Q29 (7 marks): a tangent is perpendicular to the radius, and tangents from one point are equal.
Why is a tangent perpendicular to the radius? — Class 10Real Numbers
Q1, Q2, Q3, Q26 (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 10Linear Equations
Q6, Q32 (6 marks): solving a pair of equations, graphing it, and when a pair is consistent.
When do two linear equations have no solution? — Class 10Arithmetic Progressions
Q7, Q20, Q36 (6 marks): the nth term and the sum of n terms.
Arithmetic vs Geometric Progression — why doubling always wins eventuallyCoordinate Geometry
Q9, Q23, Q27 (6 marks): the distance, mid-point and section formulas.
Why is the distance formula just Pythagoras? — Class 10Midpoint Formula vs Section Formula — Class 10Statistics
Q17, Q35 (6 marks): mean, median and mode of grouped data.
Mean vs Median vs Mode — why one outlier can lie to youQuadratic Equations
Q33 (5 marks): the discriminant, standard form and solving by factorising.
Why does a quadratic have at most two real roots? — Class 10Polynomials
Q4, Q5, Q21 (4 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
Q18, Q31 (4 marks): favourable outcomes over total outcomes, and sure events.
Why is probability always between 0 and 1? — Class 10Stuck on a step in any solution?
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The LCM of and is:
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