Tag: maths

Questions Related to maths

If a number, when divided by $4$, is reduced by $21$, the number is:

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. $18$

  2. $20$

  3. $28$

  4. $38$

Show answer
Correct Option: C
Explanation:
Let $x$ be the number.
If a number is divided by the $4$ the expression becomes $\dfrac{x}{4}$
If a number, when divided by $4$, is reduced by $21$, then the equation is
$\dfrac{x}{4}=x-21$
$\Rightarrow\,\dfrac{x}{4}-x=-21$
$\Rightarrow\,\dfrac{x-4x}{4}=-21$
$\Rightarrow\,-3x=-21\times 4$
$\Rightarrow\,x=\dfrac{21}{3}\times 4=7\times 4=28$
$\therefore\,$,the number is $28$

The product of two numbers is 1296. If one number is 16 times the other, then the two numbers are 

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. 144, 25

  2. 81, 49

  3. 144, 9

  4. none of these

Show answer
Correct Option: C
Explanation:

Let the first number be $x$. Then, other number is $16x$.


Now, $x \times 16x =1296$

$16x^2=1296$
$x^2=81$
$x=9$
$16x=16\times 9=144$

Thus, the two numbers are $9$ and $144.$

The average age of the mother and her six children is 12 years which is reduced by 5 years if the age of mother is excluded. How old is the mother?

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. 40 years

  2. 42 years

  3. 48 years

  4. 50 years

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Correct Option: A

Two years ago, a father was five times as old as his son. Two years later, father age will be 8 more than three times the age of the son. Find the sum of present ages of father and son.

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. 62 years

  2. 52 years

  3. 42 years

  4. 34 years

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Correct Option: A

If the sum of five consecutive even numbers is $240$ then find the middle number.

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. $45$

  2. $50$

  3. $44$

  4. $48$

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Correct Option: A

If $50$ is subtracted from two-third of a number, the result is equal to sum of $40$ and one-fourth of that number. What is the number? 

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. $174$

  2. $216$

  3. $246$

  4. $336$

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Correct Option: A

The average of 9  consecutive numbers with difference of 9 is 79 , then with smallest number  among them ?

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. 43

  2. 34

  3. 52

  4. 44

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Correct Option: A

The two parts of $100$ for which the sum of double of first and square of part is minimum. value of the smaller part is:

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. $48$

  2. $1$

  3. $32$

  4. $16$

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Correct Option: A

find the sum of two numbers ,whose ratio is 7:19 and their difference is 12

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. 22

  2. 26

  3. 24

  4. 23

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Correct Option: A

A number is $\dfrac{2}{5}$ of the second number seum of the two number is $70$; then the number are 

maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

  1. $20,30$

  2. $20,40$

  3. $50,20$

  4. $20,15$

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Correct Option: A