Tag: maths

Questions Related to maths

If the sum of two consecutive odd numbers is 2004, then the smaller of the two numbers could be

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 2001

  2. 1001

  3. 1003

  4. 1

Show answer
Correct Option: B
Explanation:

Let the two consecutive odd numbers are x and x+2
$x+x+2 = 2004$
$x+x+2-2 = 2004 -2 $ (Subtract 2 from both the sides)
$2x = 2002$
$\frac{2x}{2} = \frac{2002}{2}$ (Divide 2 from both the sides)
$x = 1001$
Hence two numbers are 1001 and 1003

How many times does the sum of 375 and 125 contain their difference?

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. $5$

  2. $4$

  3. $3$

  4. $2$

Show answer
Correct Option: D
Explanation:

The sum of  375 and 125 $=375+125 = 500$
The difference of 375 and 125 $ = 375-125 = 250$
Hence Sum contains $500 \div 250 = 2 $ times their differences.

A man can row 16 km downstream in one hour but upstream he takes twice the time then the speed of the current is

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 8 km/h

  2. 12 km/h

  3. 4 km/h

  4. 2 km/h

Show answer
Correct Option: C
Explanation:

The man down stream is 16 km in one hour and he take twice time in upstream 

Then he take time 2 hour in 16 km 
So speed in upstream =$\frac{16}{2}=8 km /hr$
Then current spread =$\frac{16-8}{2}=4$ km/hr 

If a=2, b=3, c=4, then the difference between $\displaystyle 2\frac{3}{4}$ and $\displaystyle b\frac{a}{c}$ is

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. $-1/4$

  2. $1/4$

  3. $-3/4$

  4. $5/4$

Show answer
Correct Option: C
Explanation:

If a=2 ,b=3 and c=4

Then $b\tfrac{a}{c}=3\tfrac{2}{4}=3\tfrac{1}{2}$
Then difference between=$2\tfrac{3}{4}-3\tfrac{1}{2}=\frac{11}{4}-\frac{7}{2}=\frac{11-14}{4}=\frac{-3}{4}$

If 125 x centimetre per second = (x+7) km/hour then the value of x is

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 4

  2. 3

  3. 2

  4. 1

Show answer
Correct Option: C
Explanation:

Given 125 x cm \second=(x+7)x km\hr 

WE know that 125 cm \ sec =4.5 km \ hr
$\therefore 125x cm\ sec =4.5 x km/hr$
Then $4.5 x=(x+7)\Rightarrow 4.5x-x=7\Rightarrow 3.5 x=7 \Rightarrow x=2$

If 5 labourers can make 5 mats in 5 hours then the number of mats that 10 labourers can make in 10 hours are

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 10

  2. 20

  3. 15

  4. 100

Show answer
Correct Option: B
Explanation:

Given 5 mates in 5 hours makes 5 laborers

Then 10  laborers can make in 10 hours =$\frac{5\times 10\times 10}{5\times 5}=20$

The average weight of 7 men is diminished by 3 kg when one of them who weighs 73 kg is replaced by a new man then the weight of the new man is 

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 50 kg

  2. 52 kg

  3. 53 kg

  4. 54 kg

Show answer
Correct Option: B
Explanation:

The averages weight of seven man diminished by 3 kg .Then total weight diminished by $3\times 7=21 kg $

If one of them whose weight is 73 kg is replased by anew man 
Then weight of new man =72-21=52 kg

What number should be subtracted from each of the numbers 54, 71, 75 and 99, so that the remainders may be in proportion?

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 5

  2. 4

  3. 3

  4. 2

Show answer
Correct Option: C
Explanation:

Let the number to be subtracted is $x$

$(54-x),  (71-x),   (75-x)$  and $ (99-x)$ are in proportion

$\Rightarrow \dfrac{54-x}{71-x}=\dfrac{75-x}{94-x}$ Which is true if $x=3$


$\Rightarrow \dfrac{54-3}{71-3}=\dfrac{75-3}{94-3}$

$\Rightarrow \dfrac{51}{68}=\dfrac{72}{91}$

i.e $\Rightarrow \dfrac{3}{4}=\dfrac{3}{4}$

Then subtracted $3$ in these number may be in proportion  

Sum of the greatest 8 digit number and the smallest 9 digit number is

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 1,99,99,999

  2. 19,99,99,999

  3. 99,99,99,999

  4. 1,00,00,999

Show answer
Correct Option: B
Explanation:

Greatest - 8 digit no. 99999999
Smallest - 9 digit no. $\underline {100000000}$
                                  $=\underline {199999999}$

A student was asked to multiply a certain number by 3 and to add 2 to it, but he divided the number by 3 and subtracted 2 from it and got the number 1. The correct answer is

maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

  1. 9

  2. 25

  3. 29

  4. none of these

Show answer
Correct Option: C
Explanation:

Let the certain number be x
As per problem,
$\Rightarrow \frac { x }{ 3 } -2=1$
 $\Rightarrow \frac { x-6 }{ 3 } =1$
 $\Rightarrow x-6=3$
 $\Rightarrow x=9$
The correct answer will be $9\times 3+2=27+2=29$