Quantitative Aptitude - Arithmetic Ability Questions

For an income of Re. 1 in 9% stock at 96, investment = Rs. 96/9 = Rs.32/3

For an income Re. 1 in 12% stock at 120, investment = Rs. 120/12 = Rs. 10.

Ratio of investments =(32/3) : 10 = 32 : 30 = 16 : 15.

Time = (100 x 81)/(450 x 4.5) years

= 4 years.

Area of field = 12*5x+3x*24 = 96x sq.m  

96x = 1440       => x =144096 = 15  

Hence, the length of longer parallel side = 5x = 75m

Ram age when he was born = 0 years
=> His brother's age = 6 year
=> His father's age = brother age + 32years = 6+32 = 38
=> His mother's age = father's age - 3 = 35
So sister's age = 35-25 = 10years.

Let the first number be K and second number be L
Then, 2K + 3L = 100.....(1)
3K + 2L = 120.......(2)
solving (1)&(2), we get
K = 32 and L = 12

Hence the largest number is 32.

Let the slower pipe alone fill the tank in x minutes. 

Then,faster pipe will fill it in x/3 minutes. 

=>1x+3x=136 =>4x=136 =>x=144mins

In a circle of n different persons, the total number of arrangements possible = (n - 1)!
Total number of arrangements = n(S) = (15 – 1)! = 14 !
Taking three persons as a unit, total persons = 13 (in 4 units)
Therefore no. of ways for these 13 persons to around the circular table = (13 - 1)! = 12!
In any given unit, 3 particular person can sit in 3!. Hence total number of ways that any three person can sit =
n(E) = 12! X 3!
Therefore P (E) = probability of three persons sitting together = n(E) / n(S) = 12! X 3 ! / 14!
= 12!x3x2 / 14x13x12! = 6/14x13 = 3/91

16 : 56 :: 32 : ?

Let the required number be 'n'

The given numbers follow a logic that,

16/56 = 2/7

=> 32/n = 2/7

=> 32 x 7/2 = n

=> n = 112.

Hence, 16 : 56 :: 32 : 112.