Aptitude and Reasoning Questions

Let the cost price of a ball is Rs.x
Given, on selling 17 balls at Rs. 720, there is a loss equal to the cost price of 5 balls
The equation is :
17x - 720 = 5x
Solving the equation
we get x = 60
Therefore, cost price of a ball is Rs. 60.

? = (3 + 4 - 2 - 1) + ( 1/6 + 1/2 - 2/3 - 11/12) 

= 4 + [(2+6-8-11)/12] 

= 4 - (11/12 )= 31/12.

The given number series is 8, 11, 19, 23, 32, ?

It follows a pattern that

8 + 11 = 19

11 + 12 = 23

19 + 13 = 32

23 + 14 = 37

32 + 15 = 47

....

Hence, the next number in the given series = 37.

Let the required no of working hours per day be x.

More pumps , Less working hours per day  (Indirect Proportion)

Less days, More working hours per day      (Indirect Proportion)

 Pumps4 : 3Days1 : 2⋮⋮ 8:x

=> (4 * 1 * x) = (3 * 2 * 8)

=> x=12

Let the speed of the boat = p kmph

Let the speed of the river flow = q kmph

From the given data,

2 x 28p + q = 28p - q

=> 56p - 56q -28p - 28q = 0

=> 28p = 84q

=> p = 3q.

Now, given that if

$$\begin{gathered} 283q + 2q + 283q - 2q = 67260 \\ => 285q + 28q = 67260 \\ => q = 3 kmph \\ => x =3q = 9 kmph \end{gathered}$$

Hence, the speed of the boat = p kmph = 9 kmph and the speed of the river flow = q kmph = 3 kmph.

Let   A = Event that A speaks the truth

B = Event that B speaks the truth 

Then P(A) = 75/100 = 3/4

P(B) = 80/100 = 4/5

P(A-lie) = 1-34= 1/4 

P(B-lie) = 1-45= 1/5

Now, A and B contradict each other =[A lies and B true] or [B true and B lies]

 = P(A).P(B-lie) + P(A-lie).P(B) 

 = 35*15+14*45=720  

 = 720*100= 35%