Tag: maths

Questions Related to maths

The straight line joining the mid-points of the opposite sides of a parallelogram divides it into two parallelogram of equal area  

  1. True

  2. False


Correct Option: A

In a $\triangle DEF$; $A,B$ and $C$ are the mid-points of $EF,FD$ and $DE$ respectively. If the area of $\triangle DEF$ is $14.4{ cm }^{ 2 }$, then find the area of $\triangle {ABC}$.

  1. $1.75$cm

  2. $2.54$cm

  3. $3.2$cm

  4. $3.6$cm


Correct Option: D
Explanation:

Fact: Using mid-point theorem $\dfrac{\Delta{DEF}}{\Delta{ABC}}=4$


Here $\Delta{DEF}=14.4$ cm$^2$ is given 
Hence are of triangle $ABC $ is given by $ \dfrac{14.4}{4}=3.6$ cm$^2$ 

In a $\triangle ABC$, if $D, E, F$ are the midpoints of the sides $BC, CA, AB$ respectively then $\overline {AD} + \overline {BE} + \overline {CF} =$

  1. $\overline {0}$

  2. $\overline {AE}$

  3. $\overline {BD}$

  4. $\overline {CE}$


Correct Option: A

A cross section at the midpoint of the middle piece of a human sperm will show

  1. Centriole, mitochondria and 9 +2 arrangement of microtubules.

  2. Centriole and mitochondria

  3. Mitochondria and 9+2 arrangement of microtubules.

  4. 9+2 arrangement of microtubules only.


Correct Option: C
Explanation:

The middle piece is the tubular structure in which mitochondria are spirally arranged and it also has the beginning part of the flagellum. The sperm tail or the flagellum is based upon unique 9+2 arrangement. This arrangement refers to the nine peripheral, symmetrically arranged microtubule doublets.
Thus, the cross-section of the middle piece of sperm will show mitochondria and 9+2 arrangement of microtubules.
Hence, the correct answer is option (C), 'Mitochondria and 9+2 arrangement of microtubules'.

Factorise ${\left( {3 - 4y - 7{y^2}} \right)^2} - {\left( {4y + 1} \right)^2}$ 

  1. $\left( {4 - 7{y^2}} \right)\left( {2 - 8y - 7{y^2}} \right)$

  2. $\left( {7{y^2} - 4} \right)\left( {2 - 8y - 7{y^2}} \right)$

  3. $\left( {4 - 7{y^2}} \right)\left( {7{y^2} + 8y - 2} \right)$

  4. $\left( {7{y^2} - 4} \right)\left( {7{y^2} - 8y - 2} \right)$


Correct Option: A
Explanation:

We have,

${\left( {3 - 4y - 7{y^2}} \right)^2} - {\left( {4y + 1} \right)^2}$ 

We know that
$a^2-b^2=(a+b)(a-b)$

Therefore,
$\Rightarrow (3 - 4y - 7y^2+4y + 1)(3-4y-7y^2-4y-1) $ 

$\Rightarrow (4 - 7y^2)(2-8y-7y^2) $ 

Hence, this is the answer.

Factorise :

$4x+12$

  1. $4(x+2)$

  2. $4(x+3)$

  3. $3(x+4)$

  4. none of these


Correct Option: B
Explanation:

$4x+12=4(x+3)$

Factorize : $y^2 + 100y$
  1. $y(y+100)$

  2. $y^2(y+100)$

  3. $y(y^2+100)$

  4. none of these


Correct Option: A
Explanation:

We need to find value of $y^2+100y$

Taking $y$ common, we get $y(y+100)$.
Hence, option A is correct.

If (x+1) is a factor of $\displaystyle x^{3}+11x^{2}+15x+a$ then the value of 'a' is

  1. 2

  2. 3

  3. 5

  4. 4


Correct Option: C
Explanation:

$x+1\div x^{3}+11x^{2}+15x+a\setminus x^{2}+10x+5$

                $x^{3}+x^{2}$ ( subtracted)
               ..............................................................
                               $10x^{2}+15x+a$
                               $10x^{2}+10x$ ( subtracted)
                            ....................................................................
                                          $5x+a$
                                          $5x+5$  ( subtracted)
.....................................................................................................
                                             a-5
If x+1 is the factor of $x^{3}+11x^{2}+15x+a$
Then a-5=0 or a=5

Factorization is the  ......... process of multiplication.

  1. equal

  2. same

  3. inverse

  4. common


Correct Option: C
Explanation:

Factorization is the inverse process of multiplication.

________ is a method of writing numbers as the product of their factors or divisors.

  1. Polynomial

  2. Factorisation

  3. Division algorithm

  4. Quadratic equation


Correct Option: B
Explanation:

Factorisation is a method of writing numbers as the product of their factors or divisors.
Example: $4x^2+2x$ is a factor $2x(2x+1)$
By multiplying the factor we get the original number.