Quantitative Aptitude - Arithmetic Ability Questions

let the radius of the pool be Rft

Radius of the pool including the wall = (R+4)ft

Area of the concrete wall = πR+42-R2=πR+4+RR+4-R = 8πR+2 sq feet

=> 8πR+2 = 1125πR2 =>11R2 =200R+2

Radius of the pool R = 20ft

Let the numbers be x and 1365+x

Then 1365+x = 6x+15 

=> x = 270

Number of ways of choosing 2 black pens from 5 black pens in 5C2 ways.

Number of ways of choosing 2 white pens from 3 white pens in 3C2 ways.

Number of ways of choosing 2 red pens from 4 red pens in 4C2ways.

By the Counting Principle, 2 black pens, 2 white pens, and 2 red pens can be chosen in 10 x 3 x 6 =180 ways.

Possibilities     Bowlers      Batsmen         Number of ways

                         6               9

         1              4                7              (6C4*9C7)

         2              5                6              6C5*9C6

         3              6                5              6C6*9C5

6C4*9C7 = 15 x 36 = 540

6C5*9C6 = 6 x 84 = 504

 6C6*9C5= 1 x 126 = 126

Total = 1170

Ratio of Milk and water in a vessel A is 4 : 1

Ratio of Milk and water in a vessel B is 3 : 2

Ratio of only milk in vessel A = 4 : 5

Ratio of only milk in vessel B = 3 : 5

Let 'x' be the quantity of milk in vessel C

Now as equal quantities are taken out from both vessels A & B

=> 4/5     :     3/5
               x 
  3/5-x          x - 4/5

=> 35-xx-45 = 11 (equal quantities)

=> x = 7/10

Therefore, quantity of milk in vessel C  = 7

=> Water quantity = 10 - 7 = 3

Hence the ratio of milk & water in vessel 3 is 7 : 3 

The hands of a clock coincide 11 times in every 12 hours (Since between 11 and 1, they
coincide only once, i.e., at 12 o'clock).

The hands overlap about every 65 minutes, not every 60 minutes.
The hands coincide 22 times in a day.

area of a square = a² sq cm

length of the diagonal = 2a cm

area of equilateral triangle with side  2a= 34*2a2
required ratio = 34*2a2:a2=3:2