Tag: decimal fractions

Quizzes (26) Questions (52)

Questions Related to decimal fractions

Multiple choice maths decimal fractions rounding decimals non-terminating recurring decimals in rational numbers rounding off decimals rounding of decimals

For rational numbers, $x$ and $y,$ if $x > y,$ then which of the following is always a positive rational number?

  1. $ y - xy$
  2. $ xy-x$
  3. $ y-x$
  4. $ x- y $
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
If $x>y$

$y-xy\rightarrow $ can be both positive and negative.

Example coside $x>1$ & $y>0$

$\left(y-xy\right)<0$

$xy-x\rightarrow $ can be both positive and negative 

$y-x\rightarrow $ always negative

$\boxed {x-y\rightarrow always\ positive\ since\ x>y}$
Multiple choice maths decimal fractions rounding decimals non-terminating recurring decimals in rational numbers rounding off decimals rounding of decimals

$0.\overline{5}$ in the form of $\frac{p}{q}$ is :

  1. $\dfrac{9}{5}$
  2. $\dfrac{5}{10}$
  3. $\dfrac{5}{9}$
  4. $\dfrac{10}{5}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$Let\quad x=.555....\ On\quad multiplying\quad by\quad 10\quad on\quad both\quad sides\quad \ 10x=5.555....\ On\quad subtracting\quad both\quad equations\quad \ 9x=5\ x=\dfrac { 5 }{ 9 } \ $

Hence, correct answer is option C.

Multiple choice maths decimal fractions rounding decimals non-terminating recurring decimals in rational numbers rounding off decimals rounding of decimals

If $x$ and $y$ are positive real number, then which of the following is correct?

  1. $x > y \Rightarrow -x > -y $
  2. $x > y \Rightarrow -x < -y $
  3. $x > y \Rightarrow \dfrac{1}{x} > \dfrac{1}{y} $
  4. $x > y \Rightarrow \dfrac{1}{x} < \dfrac{-1}{y} $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If $x$ and $y$ are positive number and $x>y$, then 

$\Rightarrow -x<-y$ 
Also, $x>y$ $\Rightarrow \dfrac{1}{x}<\dfrac{1}{y}$
Hence, B is correct option.

Multiple choice maths decimal fractions rounding decimals non-terminating recurring decimals in rational numbers rounding off decimals rounding of decimals

In expressing a length $81.472 \ km$ as nearly as possible with three significant digits, the percent error is

  1. $0.34\%$
  2. $0.034\%$
  3. $0.0034\%$
  4. $0.0038\%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$81.472 km = 81472$ meters $= 81500$ meters with three significant digits.
$\displaystyle \therefore Error\%=\frac{81500-81472}{81472}\times 100=0.034\%$