Tag: decimal fractions

Questions Related to decimal fractions

On rounding off the decimal part of $32.4$ to the nearest one, we get

  1. $30$

  2. $32$

  3. $33$

  4. $35$


Correct Option: B
Explanation:

In $32.4$, digit $4$ is less than $5$ so we will round off to $32.$
After rounding of $32.4$ will become $32.$

While rounding off, if the digit to be dropped is less than $5$, then the preceding digit:

  1. increases by $1$

  2. remains unchanged

  3. decreases by $1$

  4. None of the above


Correct Option: B
Explanation:
When rounding, you examine the digit following (i.e., to the right of) the digit that is to be the last digit in the rounded off number. The digit you are examining is the first digit to be dropped.

  1. If that first digit to be dropped is less than $5$ (that is, $1, 2, 3 $ or $4$), drop it, and also drop all the digits to the right of it.
  2. If that first digit to be dropped is more than $5$ (that is, $6, 7, 8$ or $9$), increase by 1 the number to be rounded, that is, the preceeding digit (to the digit being dropped).
Thus, in our case, since the digit to be dropped is less than $5$, we make no change to the preceding digit. 

Sohan wishes to order salt for himself, but the salt is only sold in $30$-pound bags. He currently has $75$ pounds of salt, and he needs to have a minimum of $200$ pounds. Determine the inequality which shows the possible values for the number of bags, b, that Macro needs to order in order to meet his minimum requirement.

  1. $\displaystyle b\ge 4$

  2. $\displaystyle b\ge 5$

  3. $\displaystyle b\ge 6$

  4. $\displaystyle b\ge 7$


Correct Option: B
Explanation:

Sohan needs to have $200$ pounds but he currently has $75$ pounds

And bags sold only $30$ pounds bag.
Then sohan take bags in $75$ pounds $=$ $\dfrac{75}{30}=2.5$ says 2
But he needed bages in $200$ pounds $=$ $\dfrac{200}{30}=6.67$ says 7
Then the inequality of number of bags (b) $=6.67-2.5=4.16$ says $5$
Hence, option B is correct.

66.7 can be approximated to

  1. 67

  2. 92

  3. 88

  4. 127


Correct Option: A
Explanation:

Given 66.7

As we can see number after decimal is more than 5 so approximated value is 67

Choose the correct alternative.
If $\bar {d}=-20.83,\bar {x}=254.17$, then $A=?$

  1. $270$

  2. $275$

  3. $233.34$

  4. $12.20$


Correct Option: A

List T consists of 30 positive decimals, none of which is an integer, and the sum of the 30 decimals is S.The estimated sum of the 30 decimals, E, is defined as follows. Each decimal in T whose tenths digit is even is rounded up to the nearest integer, and each decimal in T whose tenths digit is odd is rounded down to the nearest integer; E is the sum of the resulting integers. If $\displaystyle \frac { 1 }{ 3 } $ of the decimals in T have a tenths digit that is even, which of the following is a possible value of E- S ? 
I. -16
II. 6
III.10

  1. I only

  2. I and II only

  3. I and III only

  4. II and III only

  5. I, II and III


Correct Option: B

Find the value to three places of decimal of  the following. It is given that $\sqrt{2}=1.414, \sqrt{3} = 1.732, \sqrt{5} = 2.236$ and $\sqrt{10}=3.162.$ 


$\dfrac{\sqrt{5}+1}{\sqrt{2}}$

  1. $2.288$

  2. $1.2845$

  3. $3.629$

  4. None of the above


Correct Option: A
Explanation:
Given,

$\dfrac {\sqrt 5+1}{\sqrt {2}}$

$=\dfrac {2.236+1}{1.414}$

$=2.288$

What is $4,563,021 \div 10^5$, rounded to the nearest whole number?

  1. 45

  2. 44

  3. 46

  4. 47


Correct Option: C
Explanation:

To divide by a positive power of 10, shift the decimal point to the left. This yields 45.63021. To round to the nearest whole number, look at the tenths place. The digit in the tenths place, 6, is more than 5. Therefore, the number is closest to 46.

Round off each of the following as required.

$5.5493$ correct to two decimal places.

  1. $5.00$

  2. $5.54$

  3. $5.50$

  4. $5.55$


Correct Option: D
Explanation:

As the third digit is greater than $5$, the second digit $4$ can be rounded to $5$.
Thus, rounding off $5.5493$ gives $5.55$.