Quantitative Aptitude - Arithmetic Ability Questions

P=4s

Let CP = 100,
42 % increase => SP = 142
10 % discount in SP => ((142 x 10)/100) = 14.2
So 1st SP = (142 - 14.2) = 127.8, again 12 % discount in 1st SP ((127.8 x 11)/100) = 14.058
2nd SP = (127.8 - 14.058) = 113.742,
So finally CP = 100, SP = 113.742, => gain = 13.742%.

Let the fraction be x/y. Then, x /(y+1) = 1/2

=> 2x - y = 1  ..........(i)and 

(x + 1) / y = 1  => x - y =  1 .......(ii)

 Solving (i) and (ii), we get :  x  = 2, y = 3. Hence, the required fraction is 2/3..

Digits are 0,1,2,3,4,5,6,7,8,9. So no. of digits are 10

First all possible case => 9(0 excluded) x 10 x 10 = 900

Second no repetition allowed =>9 x 9 x 8 = 648

Third all digits are same => 9 (111,222,333,444,555,666,777,888,999)

Three digit numbers where two of the three digits are same = 900 - 648 - 9 = 243 ;

The Multiples of 6 are 6, 12, 18, 24, 30, 36, 42, 48, 54, 60.

The Multiples of 4 are 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60.

The Common Multiples of 4 & 6 upto 60 numbers are given as 12, 24, 36, 48, 60.

let the diagonals of the squares be 2x and 5x respectively

ratio of their areas = 12*2x2 :12*5x2= 4:25

Ayush's present age = 10 years.
His mother's present age = (10 + 20) years = 30 years.
Ayush's father's present age = (30 + 5) years = 35 years.
Ayush's father's age at the time of Ayush's birth = (35 - 10) years = 25 years.

Therefore Ayush's father's age at the time of marriage = (25 - 2) years = 23 years.