2. Questions Bank
  3. 7th Class
  4. Mental Ability
  5. Algebraic Expressions

7th Class Mental Ability Algebraic Expressions Question Bank Algebra

  • question_answer
    A number is 7 less than the other and its square is 77 less than the square of the greater number. The smaller number is:

    A) 9               

    B)               1

    C) 4                

    D)               5

    E) None of these

    Correct Answer: B

    Solution :

    Explanation Let the smaller number be x. Then the larger number \[= x + 7\] \[{{\left( x + 7 \right)}^{2}}= {{x}^{2}}+ 77\] \[\Rightarrow \,\,{{x}^{2}}+14x+49={{x}^{2}}+77\] \[\Rightarrow \,\,\,14x=77-49\] \[\Rightarrow \,\,\,x=\frac{2{{{}}^{2}}}{1}\] \[\Rightarrow \,\,\,x=2\]


You need to login to perform this action.
You will be redirected in 3 sec spinner