Quantitative Aptitude - Arithmetic Ability Questions

Speed in downstream = (14 + 4) km/hr = 18 km/hr;

Speed in upstream = (14 – 4) km/hr = 10 km/hr.

Let the distance between A and B be x km. Then,

x/18 + (x/2)/10 = 19 ⇔ x/18 + x/20 = 19 ⇒ x = 180 km.

Assume the weight of alloy a is 100 kg 

Therefore, The weight of alloy B is 400kg

             Gold          silver         copper

    A       40kg          60kg          0kg

    B      140kg         160kg        100kg

  total    180kg          220kg        100kg

Therefore, Ratio of gold and silver in new alloy = 180500:200500= 36% :44%

Suppose the man works overtime for x hours.

Now, working hours in 4 weeks = (5 x 8 x 4) = 160.

Therefore,  160 * 2.40 + x * 3.20 = 432

 => 3.20x = 432 - 384 = 48

 => x = 15.

 Hence, total hours of work = (160 + 15) = 175.

From 5 consonants, 3 consonants can be selected in 5C3 ways.

From 4 vowels, 2 vowels can be selected in 4C2 ways.

Now with every selection, number of ways of arranging 5 letters is 5P5ways.

Total number of words = 5C3*4C2*5P5

                                = 10x 6 x 5 x 4 x 3 x 2 x 1= 7200

Let the present age of the man be 'P' and son be 'Q',
Given, P + Q = 64 or Q = (64 - P)
Now the man says "I am five times as old as you were, when I was as old as you are",
So, P = 5[B - (P - Q)]
We get 6P = 10Q,
Substitute value for Q,
6P = 10(64 - P),
Therefore P = 40, Q = 24.