Quantitative Aptitude - Arithmetic Ability Questions

Let the C.P be Rs.100 and S.P be Rs.x, Then
The profit is (x-100)
Now the S.P is doubled, then the new S.P is 2x
New profit is (2x-100)
Now as per the given condition;
=> 3(x-100) = 2x-100
By solving, we get
x = 200
Then the Profit percent = (200-100)/100 = 100
Hence the profit percentage is 100%

let each side of the square be a , then area = a2 

As given that The side is increased by 25%, then 

New side = 125a/100 = 5a/4 

New area = 5a42  

Increased area= 25a216-a2 

Increase %=9a2/16a2*100  % = 56.25%

The Sum of the digits in each number, Except 324 is 10.

1, 1 + 1² = 2, 2 + 2² = 6, 6 + 3² = 15, 15 + 4² = 31, 31 + 5² = 56, 56 + 6² = 92

Last number of given series must be 92 not 91.

4       30       ?     1440       7195      71940

Here the given series follows a pattern of

4

4 x 10 - 10 = 30

30 x 5 - 5  = 145

145 x 10 - 10 = 1440

1440 x 5 - 5 = 7195

7195 x 10 - 10 = 71940

Hence, the missing number is 145

Number of ways of selecting (3 consonants out of 7) and (2 vowels out of 4) = (7C3*4C2) 

= 210. 

Number of groups, each having 3 consonants and 2 vowels = 210. 

Each group contains 5 letters. 

Number of ways of arranging 5 letters among themselves = 5! = 120 

Required number of ways = (210 x 120) = 25200.