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## css       ## Friday, November 27, 2020

### Top Aptitude Questions with Easiest Short Tricks that have been asked or chances of being asked in many forth coming Comptetive Exams .

Top Aptitude Questions with Easiest  Short Tricks  that have been asked or chances of  being asked in many forth coming Comptetive Exams .

HCF : Highest Common Factor (Related )

Q : Find the greatest possible number by which when we divide the numbers  38,  66 and 80  the remainders are same ?

Solution :

38    ,      66,        80

First   Second   Third

First  Number – Second  Number

Whichever is Greater among First Number and Second Number

Substract smaller from Large  number

66-38 = 28

Third   Number – Second Number

Whichever is Greater among Second Number and Third Number

Substract smaller from Large  number

80-66 = 14

Third   Number – First  Number

Whichever is Greater among First Number and Third Number

Substract smaller from Large  number

80-38 = 42

Now we Get

28 , 14  and 42 Among these take HCF Which is 14 .

1 number,   2 number ,  3 number

Take Differences  between Numbers as described above.

Then take the HCF among them you will get the

Solution.

Q. Number Series(Related)

Find out  Question Mark in the series.

1, 2 ,11, 36, 85 ,166 , ?

Solution :

First of all take the differences between consecutive numbers

So

1, 2 , 11, 36, 85 ,166 , ?

Difference between

Two Consecutive numbers

1   9    25  49  81

12   32   52   72  9

and so on

So  112 is  121  Add 121 to 166

We get 287

Solution is 287

Q Simple Interest (SI Related)

A sum of Money becomes two times itself in

07 years at simple Rate of interest then in How many years it will become four (04) times ?

Solution:

Formula is

N1-1/ T1 =N2-1/T2

T1 = 7

T2 = ?

N1 = 2

N2 = 4

Placing All these Values

We get

2-1 / 7  =  4-1 / T2

1 / 7 =4-1 / T2

T2 = 3 x 7 = 21

Q    Time Related (Clock)

What is the Angle between hour hand and

minute hand at  4:32  ?

Solution:

4/ 32

On simplification  of 4/ 32

We get  1/8 Ratio

Formula (Short Trick)

(Minute- Hour)*2

= (32-4) *2

= 28*2

=56

If  On simplification We get  Ratio

1:3 Then

a)            1:3  = Minute * 4  + Minute /2

If  On simplification We get  Ratio

1:4 Then

b)           1:4  = Minute * 2

If  On simplification We get  Ratio

1:10 Then

c)             1:10  = Minute * 2 .5

Permutation and Combination

Q In how many different ways can the letter of the word “ADYNAMIC” be arranged so that the vowels never come together ?

Solution:

Total arrangement =

8!(Factorial) / 2! (Factorial)

Since A repeat 2 times in ADYNAMIC

Vowels in ADYNAMIC = AAI (3)

Other Words in ADYNAMIC = DYNMC

(5)

We take AAI Into one group due to all vowels so 5+1 =6

Now Vowels come Together =

6! * 3! /  2!(repeat)

Now Never comes= Total arrangement  -                                                                                                                                                            Come

= 8!(Factorial) / 2! (Factorial)

-       (6! * 3! /  2!(repeat))

While  taking commen 6! We get

7*8/2 =28    and   3!/2! = 3 *2/2  = 3

= 6!(28-3)

= 720*25

720 * 100/4

= 1800

Series (Related)

Q

What comes next in below series in place of question mark ?

12 , 12 , 18, 45 , 180

Solution: After Analyzing above series

There is a difference of one(1) in first two numbers .

So when there is a difference of one(1) in first two numbers then

We can solve it by multiplication factor.

Series will be like this  * 1, * 1.5, * 2.5,4.0

ie

12*1 =12

12*1.5 =18

18 *2.5=45

45*4.0=60

Now difference of series would be like this

1, 1.5, 2.5, 4.0

*.5, *1, * 1.5 ,* 2.0 and so on

Finally we get

Solution  : 180*6= 1080

Boat and Stream

Q A person can row a boat 17 KMPH in still water

, if he takes twice as much time to row upstream as much time to row upstream as to row downstream

in the river, calculate speed of  stream ?

Solution:

a:b= 2:1 (Given)

boat 17 KMPH

C= a-b/a+b * Boat

C=2-1/2+1 * 17

C= 1/3*17

C=17/3

So speed of stream =17/3

Probability

Q A bag contain 3 red balls , 4 black balls and 5 green balls , 3 balls are drawn randomly  Now Find the probalility of getting all balls are of green in colour ?

Solution:

3 Red balls

4 black balls

5 green balls

Total Balls =12 probalility of getting all balls are of green in colour

Total Probability

= 5C3  divide by 12 C3

If  both are same ie 3 and 3

then you can ignore 3

And get 5 *4 *3

12 *11 * 10

= 1/22

SECOND METHOD

By Formula  = nCr n!/r! *(n-r)!

= 5! / 3!*2!

=5 *4 /2

But you can prefer first method 5 *4 *3

12 *11 * 10

Mensuration(Related)

Q The Area of a square is 6084 square meters

The Breadth of a rectangle is 1/3 of the side of the square and the length of a rectangle is 3(Thrice) its breadth . What is the difference between perimeter of a square and the perimeter of a rectangle (in meter) ?

Solution :

We know that perimeter of a square is 4 *a

Where  a is the side of a square

We know that perimeter of a rectangle is 2(a+b)

Where  a and b are the length and breadth of a rectangle

Now :

Area of a square =(a)2  Given 6084

So calculate side

Under root of a is a side of a square

6084

Short Trick to calculate under root of a number

6084

Last digit is 4 so ( 2* 2=4 or 8*8=64)

2 and 4 comes at the end

Now take first two digit ie it is 60

Now 8*8 =64 so we take less then that

7*7=49

Now first digit is 7 and last digit is (we have to choose  among  2 and 8)

For this multiply (2 and 8 with first digit)

ie  7*8 =56

so first two digit ie 60 >56

so we take 8 as answer

now the square root of 6084 is 78

According to question

So Length = 3* 26

Length = 78

Perimeter of a square =4* a

= 4*78

=312

Perimeter of a rectangle = 2(L + B)

=2(78+26)

=208

So the difference between the Perimeter of a square and Perimeter of a rectangle is

312-208= 104

Solution : 104