Advertisements
Advertisements
If the sum of first 7 terms of an A.P. is 49 and that of its first 17 terms is 289, find the sum of first n terms of the A.P.
Concept: Sum of First ‘n’ Terms of an Arithmetic Progressions
How many terms of the A.P. : 24, 21, 18, ................ must be taken so that their sum is 78?
Concept: Sum of First ‘n’ Terms of an Arithmetic Progressions
Prove that `sqrt((1 - sin θ)/(1 + sin θ)) = sec θ - tan θ`.
Concept: Trigonometric Identities (Square Relations)
If the quadratic equation px2 − 2√5px + 15 = 0 has two equal roots then find the value of p.
Concept: Nature of Roots of a Quadratic Equation
Solve for x: 1 + 4 + 7 + 10 + ... + x = 287.
Concept: Sum of First ‘n’ Terms of an Arithmetic Progressions
Radha deposited ₹ 400 per month in a recurring deposit account for 18 months. The qualifying sum of money for the calculation of interest is ______.
Concept: Mathematics of Recurring Deposit (R.D.)
Which of the following equations has 2 as a root?
Concept: Nature of Roots of a Quadratic Equation
The roots of equation (q – r)x2 + (r – p)x + (p – q) = 0 are equal.
Prove that 2q = p + r; i.e., p, q, and r are in A.P.
Concept: Nature of Roots of a Quadratic Equation
Given that the sum of the squares of the first seven natural numbers is 140, then their mean is ______.
Concept: Problems Based on Numbers
If x, y and z are in continued proportion, Prove that:
`x/(y^2.z^2) + y/(z^2.x^2) + z/(x^2.y^2) = 1/x^3 + 1/y^3 + 1/z^3`
Concept: Proportion
A mixture of paint is prepared by mixing 2 parts of red pigments with 5 parts of the base. Using the given information in the following table, find the values of a, b and c to get the required mixture of paint.
| Parts of red pigment | 2 | 4 | b | 6 |
| Parts of base | 5 | a | 12.5 | c |
Concept: Direct Applications of Ratio and Proportion
While factorizing a given polynomial using the remainder and factor theorem, a student finds that (2x + 1) is a factor of 2x3 + 7x2 + 2x – 3.
- Is the student’s solution correct in stating that (2x + 1) is a factor of the given polynomial?
- Give a valid reason for your answer.
Also, factorize the given polynomial completely.
Concept: Applications of Factor Theorem
An Arithmetic Progression (A.P.) has 3 as its first term. The sum of the first 8 terms is twice the sum of the first 5 terms. Find the common difference of the A.P.
Concept: Sum of First ‘n’ Terms of an Arithmetic Progressions
Find the coordinates of the centroid P of the ΔABC, whose vertices are A(–1, 3), B(3, –1) and C(0, 0). Hence, find the equation of a line passing through P and parallel to AB.
Concept: Formula for the Centroid of a Triangle
In the given figure, AC is the diameter of the circle with center O.
CD is parallel to BE.
∠AOB = 80° and ∠ACE = 20°
Calculate:
- ∠BEC
- ∠BCD
- ∠CED

Concept: Theorems on Angles in a Circle
A manufacturing company prepares spherical ball bearings, each of radius 7 mm and mass 4 gm. These ball bearings are packed into boxes. Each box can have a maximum of 2156 cm3 of ball bearings. Find the:
- maximum number of ball bearings that each box can have.
- mass of each box of ball bearings in kg.
(Use π = `22/7`)
Concept: Mensuration of a Sphere
Prove the identity (sin θ + cos θ)(tan θ + cot θ) = sec θ + cosec θ.
Concept: Trigonometric Identities (Square Relations)
Prove the following trigonometry identity:
(sin θ + cos θ)(cosec θ – sec θ) = cosec θ ⋅ sec θ – 2 tan θ
Concept: Trigonometric Identities (Square Relations)
Jaya borrowed Rs. 50,000 for 2 years. The rates of interest for two successive years are 12% and 15% respectively. She repays 33,000 at the end of the first year. Find the amount she must pay at the end of the second year to clear her debt.
Concept: Concept of Compound Interest >> Compound Interest as a Repeated Simple Interest Computation with a Growing Principal
Mr Lalit invested Rs. 5000 at a certain rate of interest, compounded annually for two years. At the end of the first year, it amounts to Rs. 5325. Calculate
1) The rate of interest
2) The amount at the end of the second year, to the nearest rupee.
Concept: Concept of Compound Interest >> Use of Compound Interest in Computing Amount Over a Period of 2 Or 3-years
