alleryStart learning →What is the value of 87 squared minus 13 squared?
- 7400
- 7200
- 7600
- 6900
Show answer and solution
Correct answer: A. 7400
Using a^2 - b^2 = (a+b)(a-b), the value is 100 x 74 = 7400.
SSC CGL Basic Algebraic Identities and Elementary Surds — practice questions
Explore 46 free Basic Algebraic Identities and Elementary Surds questions in SSC CGL Quantitative Aptitude. Open each question or exercise to read its content, reference answers and available explanation.
Practise Basic Algebraic Identities and Elementary Surds with Quill →Basic Algebraic Identities and Elementary Surds questions and exercises with answers
Showing questions 1–30 of 46.
What is the value of 87 squared minus 13 squared?Read the answer and worked solution →A square plot of side 63 m has a square of side 37 m removed. What area is left?Read the answer and worked solution →Evaluate 1001^2 - 999^2 without squaring each number.Read the answer and worked solution →Find the value of 8.5 x 8.5 - 1.5 x 1.5.Read the answer and worked solution →If 4x^2 - 9y^2 = 60 and 2x + 3y = 10, find 2x - 3y.Read the answer and worked solution →The difference of two numbers is 3 and their product is 10. Find the sum of their squares.Read the answer and worked solution →If a + b = 7 and a^2 + b^2 = 29, then ab equals what?Read the answer and worked solution →Given x + 1/x = 3, find the value of x^3 + 1/x^3.Read the answer and worked solution →If x + 1/x = 2 for a real x, what is x^100 + 1/x^100?Read the answer and worked solution →If a + b = 10 and ab = 21, find a^3 + b^3.Read the answer and worked solution →If a + b + c = 12 and ab + bc + ca = 47, find a^2 + b^2 + c^2.Read the answer and worked solution →If a + b + c = 0, then (a^3 + b^3 + c^3)/(abc) equals what?Read the answer and worked solution →What is the value of 103 cubed?Read the answer and worked solution →Evaluate (47^3 + 53^3)/(47^2 - 47 x 53 + 53^2).Read the answer and worked solution →The expression a^3 + b^3 factorises as which product?Read the answer and worked solution →Which is the complete factorisation of x^3 + 8?Read the answer and worked solution →Which pair of cubes adds up to 1729?Read the answer and worked solution →Using (50-3)(50+3), find 47 x 53.Read the answer and worked solution →Evaluate 96 x 104 using a quick identity.Read the answer and worked solution →What is 998 x 1002?Read the answer and worked solution →The product 4.9 x 5.1 equals which value?Read the answer and worked solution →Find the value of 0.64^2 - 0.36^2.Read the answer and worked solution →The squares of two consecutive natural numbers differ by 99. Which is the larger number?Read the answer and worked solution →The difference of the squares of two consecutive integers is always what kind of number?Read the answer and worked solution →Rationalising the denominator of 1/(sqrt5 - 2) gives which value?Read the answer and worked solution →Simplify 1/(sqrt7 + sqrt6).Read the answer and worked solution →Express 6/(sqrt3 + 1) with a rational denominator.Read the answer and worked solution →Simplify (sqrt3 + sqrt2)/(sqrt3 - sqrt2).Read the answer and worked solution →Find the value of 1/(1+sqrt2) + 1/(sqrt2+sqrt3) + 1/(sqrt3+2).Read the answer and worked solution →What is the value of (sqrt5 + sqrt3)(sqrt5 - sqrt3)?Read the answer and worked solution →
Worked practice questions
A square plot of side 63 m has a square of side 37 m removed. What area is left?
- 2400 sq m
- 2600 sq m
- 2800 sq m
- 3200 sq m
Show answer and solution
Correct answer: B. 2600 sq m
Area left is 63^2 - 37^2 = (63+37)(63-37) = 100 x 26 = 2600 sq m.
Evaluate 1001^2 - 999^2 without squaring each number.
- 4000
- 2000
- 3000
- 8000
Show answer and solution
Correct answer: A. 4000
The sum is 2000 and the difference is 2, so the product is 4000.
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