Tag: maths

Quizzes (518) Questions (9324)

Questions Related to maths

Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

In what ratio must a grocer mix two varieties of pulses costing Rs.$15$ and Rs.$20$ per kg respectively so as to get a mixture worth Rs.$16.50$ kg?

  1. $3 : 7$
  2. $5 : 7$
  3. $7 : 3$
  4. $7 : 5$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Consider the amount of pulse of price $Rs15$ $=x$


And the amount of pulse of price $Rs20$ $=y$

Then the total amount of mixture $=15x+20y$

But the price per $kg$ of mixture $=Rs16.50$

So, total price of $x+y kg$ $=16.50(x+y)$

Now according to the equation 

$16.50(x+y)=15x+20y$

$16.50x+16.50y=15x+20y$

$1.50x=3.50y$

$\frac { x }{ y } =\frac { 3.50 }{ 1.50 } \ =\frac { 0.7 }{ 0.3 } =\frac { 7 }{ 3 } $

Hence, required Ratio is $7:3$

So, the Option $C$ is the correct answer.

Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

A certain amount was divided between Kavita and Reena in the ratio $4 : 3$.If Reena's share was Rs.$2400$ , then the total amount is _____ .

  1. Rs.$5600$
  2. Rs.$3200$
  3. Rs.$9600$

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
$\Rightarrow$  Ratio of Kavita and Reena amount is $4:3$.
$\Rightarrow$  Let their shares be $Rs. 4x$ and $Rs. 3x.$
$\Rightarrow$  Then, $3x = 2400$
$\Rightarrow$ $x=800$
 $\therefore$  Total amount = $4x+3x=7x=Rs.(7\times 800)=Rs.5600$
$\therefore$  The total amount is $Rs.5600.$
Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

If $A : B = 2 : 3$ and $B : C = 4 : 5$, then $C : A$ is equal to ________.

  1. $15 : 8$
  2. $12 : 10$
  3. $8 : 5$
  4. $8 : 15$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Given: $\dfrac{A}{B}=\dfrac{2}{3}$


$\Rightarrow B=\dfrac{3A}{2}$


Now, $\dfrac{B}{C}=\dfrac{4}{5}$
putting the value of B in terms of A we get

$\Rightarrow \dfrac{3A}{2C}=\dfrac{4}{5}$

$\Rightarrow \dfrac{C}{A}=\dfrac{15}{8}$

Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

If $b \neq d$, the fractions $\dfrac{ax + b}{cx + d}$ and $\dfrac{b}{d}$ are unequal if:

  1. $a = c = 1 \ and \ x \neq 0$
  2. $a = b = 0$
  3. $a = c = 0$
  4. $x _3 = 0$
  5. $ad = bc$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\cfrac { ax+b }{ cx+d } \neq \cfrac { b }{ d } \Longrightarrow adx+bd\neq bcx+bd\Longrightarrow (ad-bc)x\neq 0\ \therefore x\neq 0\quad and\quad ad\neq bc$

We know, $b \neq d$
$\therefore a=c=1$
$\therefore a=c=1 $ and $x \neq 0$

Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

Given that $\displaystyle\frac{4p + 9q}{p} = \frac{5q}{p - q}$ and $p$ and $q$ are both positive. calculate $\displaystyle\frac{p}{q}$

  1. $\displaystyle\frac{1}{3}$
  2. $\displaystyle\frac{2}{3}$
  3. $\displaystyle\frac{3}{2}$
  4. $\displaystyle\frac{3}{5}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Given 

$\dfrac{4p+9q}{p}=\dfrac{5q}{p-q}$
or, $4p^2-4pq+9pq-9q^2=5pq$
or, $4p^2=9q^2$
or, $\dfrac{p}{q}=\dfrac{3}{2}$ [Since $p$ and $q$ are both positive]

Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

The length and breadth of a rectangular field are $50\ m$ and $15\ m$ respectively. Find the ratio of the breadth to the length of the field.

  1. $3:5$
  2. $3:10$
  3. $3:15$
  4. $10:3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The length of the rectangular field is $50 m$ and breadth of the field is $15 m$.

The ratio of breadth and length is,

${\rm{breadth}}:{\rm{length}} = 15:50=\dfrac{15}{50}=\dfrac{3}{10}$

$ = 3:10$