Quantitative Aptitude - Arithmetic Ability Questions

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.

 Sum of the remaining two numbers = (3.95 * 6) - [(3.4 * 2) + (3.85 * 2)]

                                                   = 23.70 - (6.8 + 7.7) = 23.70 - 14.5 = 9.20.

Required average = (9.2 / 2) =  4.6.

Total pice of the two books = Rs. [(12 x 10) - (11.75 x 8)]

                                          = Rs. (120 - 94) = Rs. 26.

let the price of one book be Rs. x

Then, the price of other book = Rs. (x + 60% of x) = Rs.(x+(3/5)x) = Rs. (8/5)x

So,  x+(8/5)x =26 <=> x =10

The prices of the two books are Rs. 10 and Rs. 16

Let cp= 100,
35 % increase in sp=135
10 % discount in 135((135*10)/100)=13.5
so 1st sp=(135-13.5)=121.5, again 15 % discount in 1st sp((121.5*15)/100)=18.225
2nd sp=(121.5-18.225)=103.275,

so finally cp=100,sp=103.275 ,gain by 3.27%