Quantitative Aptitude - Arithmetic Ability Questions

Given the cost price of the articles = Rs. 450

To get overall 20% gain,

Total Selling Price = (20/100) x 450 = 540

One third of the CP = 1/3 x 450 = Rs. 150

But given 1/3 of articles are sold at 10% loss

S.P of 1/3 of articles = 90% of 150

= 90 x 150/100 = 135

Then, S.P on remaining 2/3 goods must be

= 450 - 135 = 405 ...........(1)

CP on remaining goods

= 2/3 x 450 = 300 ............(2)

Profit = SP - CP = 405 - 300 = 105

Profit %  = (105/300) x 100

= 35%.

Let A's 1 day's work=x and B's 1 day's work=y

Then x+y = 1/40 and 20x+60y=1 

Solving these two equations , we get : x= 1/80 and y= 1/80

Therefore B's  1 day work = 1/80

Hence,B alone shall finish the whole work in 80 days

Let inner radius be r metres. Then, 2πr = 440 ; r = 440×744= 70 m.

Radius of outer circle = (70 + 14) m = 84 m.

Total distance covered =72+14miles =154miles  

Time taken = 154*75hrs = 120 hrs =120*60min = 3 min

Let the numbers be 4x, 5x and 6x, Then, (4x + 5x + 6x ) / 3 = 25  

=> 5x = 25

=> x = 5. 

Largest number  6x = 30.

We have : ( a + b + c) / 3 = M   or (a + b + c) = 3M.

Now. a+b+c2=3M2=9M2 .

<=>a2+b2+c2+2ab+bc+ca=9M2

a2+b2+c2=9M2 ,(ab+bc+ca=0)     

Required mean =a2+b2+c23=9M23=3M2 .