Quantitative Aptitude - Arithmetic Ability Questions

A's 1 days work = 1/12 

B's 1 days work =1/6

Therefore, (A+B)'s 1 day's work= 1/12 + 1/6 = 1/4       

Therefore, Time taken by both to finish the whole work = 114 = 4 days

Alternatively :

Efficiency of A =100/12 =8.33%

Efficiency of B =100/6=16.66%

Combined efficiency of A and B both = 8.33+16.66=25%

Therefore, Time taken by both to finish the work (working together) =100/25= 4days

Here, s={H,T} and E={H}
P(E) = n(E)/n(S) = 1/2

Given that,

1st train speed = 62 km/hr 

2nd train speed  = 44 km/hr

Hence the relative speed of two trains is : 62-44 = 18 km/hr = 18×518 m/s = 5 m/s.

There fore, the first train crosses the second train i.e (85+75)mts of distance with a speed of 5m/s in, 

time = distancespeed = 85+755 = 32 sec.

Let 'd' be the distance between A and B
K -time = d/10 + d/9 = 19d/90 hours
L -time = 2d/12 = d/6 hours
We know that, 10 min = 1/6 hours
Thus, time difference between K and L is given as 10 minutes.
=> 19d/90 - d/6 = 1/6
=> (19d-15d)/90 = 1/6
=> 4d/90 = 1/6
Thus,
d= 15/4 km = 3.75 km.

hence the distance between A and B is 3.75 km.

From the given data,

Ratio of capital = 12000 : 14400 = 5 : 6

Required Difference = 

$$\begin{gathered} 6 - 56 + 5 88100 x 7500 + 12100 x 7500 \\ = 111 x 88 x 75 + 12 x 75 \\ = 600 + 900 \\ = 1500 \end{gathered}$$

-5-----------------------5-------------------20

5-(-5) = 10

20-5= 15

Ratio of cost price of book1 and book2 = 3:2 

Then cost price of book 1 is given by

(3/5) x 100 = Rs. 60.

Average speed=total distance/total time
Let distance to store be  K
then, total time =(K/20)+(K/30)=K/12
and, total time =(2K)
so average speed= 2K / (K/12) = 24kmph.