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Question 571
StructuredStandard5 marks
CBSE Class 11 Mathematics · Statistics · Mean deviation

For age classes 16–20,...,51–55 with frequencies 5,6,12,14,26,12,16,9, find mean deviation about the grouped median.

Question 572
StructuredStandard5 marks
CBSE Class 11 Mathematics · Introduction to Three Dimensional Geometry · Section formula and loci

The origin is the centroid of P(2a,2,6), Q(−4,3b,−10), R(8,14,2c). Find a,b,c.

Question 573
StructuredStandard5 marks
CBSE Class 11 Mathematics · Conic Sections · Circles

A radius-5 circle has its centre on the x-axis and contains (2,3). Find both possible equations.

Question 574
StructuredStandard5 marks
CBSE Class 11 Mathematics · Sequences and Series · Sequences

Let a₁=−1 and aₙ=aₙ₋₁/n for n≥2. Find the first five terms and their series.

Question 575
StructuredStandard4 marks
CBSE Class 11 Mathematics · Linear Inequalities · One-variable inequalities

Solve \(\frac12(\frac{3x}{5}+4)\ge\frac13(x-6)\) for real \(x\).

Question 576
StructuredStandard4 marks
CBSE Class 11 Mathematics · Trigonometric Functions · Trigonometric functions

Complete every requested part of exercise 3.2, question 5: tan x = – , x lies in second quadrant. 12 Find the values of the trigonometric functions in Exercises 6 to 10.

Question 577
StructuredStandard3 marks
CBSE Class 11 Mathematics · Relations and Functions · Relations

On \(\mathbb N\), define \(R\) by \(y=x+5\) for natural \(x<4\). Write the roster, domain and range.

Question 578
StructuredStandard5 marks
CBSE Class 11 Chemistry · Hydrocarbons · Aromaticity and benzene reactions

For each of the three illustrated cyclic conjugated systems, state why it fails the conditions for aromaticity.

Question 579
StructuredStandard4 marks
CBSE Class 11 Chemistry · Organic Chemistry: Some Basic Principles and Techniques · Electronic effects and reaction mechanisms

Define electrophiles and nucleophiles and illustrate each with suitable examples.

Question 580
StructuredStandard7 marks
CBSE Class 11 Chemistry · Redox Reactions · Oxidising and reducing behaviour

How do you count for the following observations ? (a) Though alkaline potassium permanganate and acidic potassium permanganate both are used as oxidants, yet in the manufacture of benzoic acid from toluene we use alcoholic potassium permanganate as an oxidant. Why ? Give a balanced redox equation for the reaction. (b) When concentrated sulphuric acid is added to an inorganic mixture containing chloride, we get colourless pungent smelling gas HCl, but if the mixture contains bromide then we get red vapour of bromine. Why ?