Quantitative Aptitude - Arithmetic Ability Questions

Let the numbers be x, x+1, x+2 

Then x + x+1 + x+2 = 42

           =>  3x + 3 = 42

           => 3x = 39 

          =>  x = 13

The numbers would be 13, 14, 15 

Therefore, Sum of the digits of middle number = 1+4 = 5

P(black ball)=3/12

P(red ball)=5/12

P(black or red)=3/12+5/12=2/3

Speed of the train relative to man

= (125/10) m/sec = (25/2) m/sec.

[(25/2) x (18/5)] km/hr = 45 km/hr.

Let the speed of the train be 'x' km/hr.

Then, relative speed = (x - 4) km/hr.

x - 4 = 45 => x = 49 km/hr.

When A runs 1000 m, B runs 900 m and when B runs 800 m, C runs 700 m.

When B runs 900 m, distance that C runs = (900 x 700)/800 = 6300/8 = 787.5 m.

In a race of 1000 m, A beats C by (1000 - 787.5) = 212.5 m to C.

In a race of 600 m, the number of meters by which A beats C

= (600 x 212.5)/1000 = 127.5 m.

Given Circumference of a circular base of a cylinder = 44 cm

We know that Circumference of a circle = $$\begin{gathered} 2πr = 44 \\ ⇒r = 22π \end{gathered}$$

Now given the height of a cylinder h = 15 cm

Volume of a cylinder V = πr2h = π22π215 = 22 x 22 x 153.14 = 2311 cm3.

Let the efficiencies of filling pipes is 4p and 5p respectively.

Efficiency of pipe which empty the tank = 2/3 x 9p/2 = 3p

Total work = 3p x 36 = 108p

Time to fill the tank by both the pipes = 108p/9p = 12 min.

% Decrease in Width = 50150x100

= 33.33%