Quantitative Aptitude - Arithmetic Ability Questions

required area = (area of an equilateral triangle of side 7 cm)- (3 * area of sector with à = 60 degrees and r = 3.5cm)
34*7*7-3*227*3.5*3.5*60360 sq cm

=34*49-11*0.5*3.5 sq cm

= 1.967 sq cm

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%

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.

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