Tag: mental additions and subtractions

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

The given table shows the average temperature of some cities of India in a particular month.

City Average maximum temperature Average minimum temperature
New Delhi $39^oC$ $27^o$
Mumbai $36^oC$ $19^oC$
Ahemdabad $37^oC$ $19^oC$
Chennai $42^oC$ $26^oC$
Kolkata $38^oC$ $24^oC$

Which city has the highest difference its average maximum temperature and average minimum temperature?

  1. Kolkata

  2. Mumbai

  3. Chennai

  4. Ahemdabad
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Highest difference of arg maximum temperature & arg minimum temperature.

New Delhi = $39^{\circ}-27^{\circ}=12^{\circ}C$

Mumbai = $36^{\circ}-19^{\circ}=17^{\circ}C$

Ahmadabad = $37^{\circ}-19^{\circ}=18^{\circ}C$

Chennai = $42^{\circ}-26^{\circ}=16^{\circ}C$

Kolkata = $38^{\circ}-24^{\circ}=14^{\circ}C$

$\therefore $ Highest difference = $18^{\circ}C$ in city Ahmadabad.
Multiple choice maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

If average of $6$ consecutive numbers is $48$, what is the difference between the smallest and the largest numbers ?

  1. $5$
  2. $10$
  3. $9$

  4. data inadequate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the $6$ numbers are $x, x+1, x+2, x+3, x+4, x+5$.

Since,
$average=48$
$\dfrac{x+x+1+x+2+x+3+x+4+x+5}{6}=48$
$6x+15=288$
$6x=273$
$x=45.5$
So,
The smallest number $=45.5$
The largest number $=x+5=45.5+5=50.5$
Difference $=50.5-45.5=5$

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

The additive inverse of $\sqrt { 3 } -2\quad is$_____________

  1. $\sqrt { 3 } +2$
  2. $-\sqrt { 3 } +2$
  3. $-\sqrt { 3 } -2$
  4. $\sqrt { 3 } +\sqrt { 2 } $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The additive inverse of a number a is the number that, when added to a, yields zero. 
This number is also known as the opposite (number), sign change, and negation.

$Additive \ Inverse \ of (\sqrt {3}-2 )\ is$
$\rightarrow -(\sqrt{3}-2)$
$\rightarrow -\sqrt{3}+2$
$\rightarrow B \ is \ correct \ answer$
Multiple choice maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

which is the number formed by $34 TL,2TL, 4TH, 5H, 2T$ and $5U$

  1. $54,04,525$
  2. $3, 40, 24, 525$
  3. $24, 34, 255$
  4. $52, 34, 245$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
34 Ten lakhs =      34,00,000
2 Ten lakhs =        20,00,000
4 Ten thousands = 4,000
5 hundreds =          500
2 tens =                   20
5 units =                  5
                            ____________
                               54,04,425
Multiple choice maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

State whether the following statement is True or False.
The predecessor of a two digit number is never a single digit number.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

False, since we can clearly analyse that predecessor of $10$ is 

$10-1=9$
And $9$ is a single digit number.
Hence predecessor of two digit number is single digit number.