Quantitative Aptitude - Arithmetic Ability Questions

Given equation  5x-17 = -x+7

Add 1x to each side of the equation

5x-17+x = -x+7+x

6x=24

x=4

                                                               Father           Son

5years ago the age of the father & son           5X                X

present the age of the father & son              5X+5             X+5

(present age of father) + (present age of son) = 70

       (5x+5)                 +        (x+5)              = 70

 Then you will get X = 10

Present age of the son (x+5) = 15

P.W = Rs.( 2562 - 122) = Rs.2440 

S.I on Rs.2440 for 4 months is Rs.122 

Rate = (100 x 122)/(2440 x [1/3]) % = 15%

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

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

1/x + 3/x = 1/36 

Given Karthik’s age = 32 years

Karthik’s son age = 7 years

Difference between their ages = K - S = 32 - 7 = 25 years ….(1)

Now, required K = 2S ……(2)

Put (2) in (1)

2S - S = 25

=> S = 25 years

Hence, at the age of 25 years of Karthik’s son, Karthik will be twice as his son’s age.

25 - 7 = 18 years

Therefore, after 18 years the father be twice as old as the son.

SI = PTR/100

SI = PX100/100

SI = P

So, Amount=P+SI=2P→22500 = 2P→P = 11250

3/4 divided by 2

= 3/4/2

= 3/4x2

= 3/8.

Hence, 3/4 divided by 2 is equal to 3/8.