Tag: maths

Quizzes (518) Questions (9324)

Questions Related to maths

Multiple choice maths percentages finding one number as percentage of another money and metric measures as percentage expressing one quantity as a percentage of another

If $50$% of (x-y)=$30$% of $(x+y)$, then what percent of $x$ is $y$?

  1. $20$%
  2. $25$%
  3. $30$%
  4. $40$%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$50\%$ of $(x-y)=30\% (x+y)$

$\dfrac{50}{100}(x-y)=\dfrac{30}{100}(x+y)$
$5(x-y)=3(x+y)$
$5x-3x=3y+5y$
$2x=8y$
$\Rightarrow x=4y \Rightarrow y=x/4$
To find : $\left[\dfrac{y}{x}\times 100\right]$
$\dfrac{y}{x}\times 100=\dfrac{x}{4}\times \dfrac{1}{x}\times 100 =\dfrac{100}{4}=25\%$
$\therefore y$ is $25\%$ of $x$

Multiple choice maths percentages finding one number as percentage of another money and metric measures as percentage expressing one quantity as a percentage of another

$12.5\% \,of\,192 = 50\% \,of\,?$ 

  1. $48$
  2. $96$
  3. $24$

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
$12.5\% \,\, of \,192 = 50\%$ of ?

First, we will find $12.5\%\,\, of\,\, 192$

$\Rightarrow \dfrac{x}{192}\times 100= 12.5$

$\Rightarrow x=\dfrac{12.5\times 192}{100}= 24$

Now we will find of what $50\%$ will give $24$

i.e., $\dfrac{24}{y}\times 100= 50$

$y = 48$
Multiple choice maths percentages finding one number as percentage of another money and metric measures as percentage expressing one quantity as a percentage of another

Out of 800 oranges, 50 are rotten. Find the percentage of good oranges.

  1. $\displaystyle\,7\,\frac{1}{4}\%$
  2. $\displaystyle\,93\,\frac{1}{4}\%$
  3. $\displaystyle\,93\,\frac{3}{4}\%$
  4. $\displaystyle\,7\,\frac{3}{4}\%$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Good oranges are $ 800 - 50 = 750 $
So, percentage of good oranges $ = \cfrac { 750}{800} \times 100 $ %  $ = \cfrac {375}{4} $ % $ = 93 \cfrac {3}{4} $ %

Multiple choice maths percentages finding one number as percentage of another money and metric measures as percentage expressing one quantity as a percentage of another

If the price of sugar is increased by 25% today; by what percent should it be decreased tomorrow to bring the price back to the original?

  1. 25%

  2. 24%

  3. 22%

  4. 20%
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the price of the sugar today be $ 100 $
Then its price tomorrow will be  $ 125 $

So,  to bring back the price to normal it should be decreased $ \cfrac {125-100}{125} \times 100 = 20 \%$

Multiple choice maths percentages finding one number as percentage of another money and metric measures as percentage expressing one quantity as a percentage of another

The sum of two numbers is $4000$. $10\%$ of one number is $\displaystyle 6\frac{2}{3}$ $\%$ of the other The difference of the number is

  1. $600$
  2. $800$
  3. $1025$
  4. $1175$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let one number be $x$. 

Then the other number $= 4000 - x$
Given, $10\%$ of $\displaystyle x=6\frac{2}{3}\%$ of $ (4000-x)$
$\displaystyle \Rightarrow \frac{10}{100}\times x=\frac{20}{3}\times \frac{1}{100}\times (4000-x)$
$\Rightarrow 10x=\dfrac{20}{3}\times 4000-\dfrac{20x}{3}$
$\displaystyle \Rightarrow 10x+\frac{20x}{3}=\frac{20}{3}\times 4000$
$\Rightarrow \dfrac{50x}{3}=\dfrac{20}{3}\times 4000$
$\displaystyle \Rightarrow x=\frac{20\times 4000}{50}=1600$
The two numbers are $1600$ and $2400$. 
$\displaystyle \therefore$ Their difference is $2400 - 1600 = 800$.

Multiple choice maths percentages finding one number as percentage of another money and metric measures as percentage expressing one quantity as a percentage of another

If p is 6 times that of q, what percent is q less than p?

  1. $12\, \displaystyle \frac{1}{2}\, \%$
  2. $83\, \displaystyle \frac{1}{3}\, \%$
  3. $6\, \displaystyle \frac{1}{4}\, \%$
  4. $33\, \displaystyle \frac{1}{3}\, \%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$p = 6q$
$p - q = 6q - q = 5q$
$\therefore$ q is less than p by $\displaystyle \frac{p\, -\, q}{p}\, \times\, 100\, \%$
$=\, \displaystyle \frac{5q}{6q}\, \times\, 100\, \%$ $=\, 83\, \displaystyle \frac{1}{3}\, \%$

Multiple choice maths percentages finding one number as percentage of another money and metric measures as percentage expressing one quantity as a percentage of another

If 'a' is  x % more than 'b' and 'b' is y % less than 'a'. then the relation between x and y is

  1. $\displaystyle \frac{1}{x}\, +\, \displaystyle \frac{1}{y}\, =\, \displaystyle \frac{1}{100}$
  2. $\displaystyle \frac{1}{y}\, -\, \displaystyle \frac{1}{x}\, =\, \displaystyle \frac{1}{100}$
  3. $\displaystyle \frac{1}{x}\, -\, \displaystyle \frac{1}{y}\, =\, 100$
  4. $\displaystyle \frac{1}{y}\, -\, \displaystyle \frac{1}{x}\, =\, 100$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$y\, \%\, =\, \displaystyle \frac{100\, \times\, x}{100\, +\, x} \%$


$\Rightarrow y\, =\, \displaystyle \frac{100\, \times\, x}{100\, +\, x}$

$\Rightarrow \displaystyle \frac{1}{y}\, =\, \displaystyle \frac{100\, +\, x}{100\, \times\, x}\, =\, \displaystyle \frac{1}{x}\, =\, \displaystyle \frac{1}{100}$

$\Rightarrow \displaystyle \frac{1}{y}\, -\, \displaystyle \frac{1}{x}\, =\, \displaystyle \frac{1}{100}$