Quantitative Aptitude - Arithmetic Ability Questions

C520 = 15504

Let the distance between home and school is 'x'.
Let actual time to reach be 't'.
Thus, x/4 = t + 4 ---- (1)
and x/6 = t - 30 -----(2)
Solving equation (1) and (2)
=> x = 98 mts.

Let number of days Charan can do the same work alone is 'd' days.

According to the given data,

$$\begin{gathered} 512 + 716 + 14d = 1 \\ 14d = 1 - 20 + 2148 \\ 14d = 48 - 4148 \\ d = 14 x 487 \\ d = 96 days \end{gathered}$$

Therefore, Charan alone can complete the work in 96 days.

Taking Log to both sides 

 we get

 n = 8           

 Given A = log321875 and B = log2432187

B = log352187 = log321875

=> A

Therefore, A = B

Let the length of the 1st train = L mts

Speed of 1st train = 48 kmph

Now the length of the 2nd train = L/2 mts

Speed of 2nd train = 42 kmph

Let the length of the bridge = D mts

Distance = L + L/2 = 3L/2

Relative speed = 48 + 42 = 90 kmph = 90 x 5/18 = 25 m/s(opposite)

Time = 12 sec

=> 3L/2x25 = 12

=> L = 200 mts

Now it covers the bridge in 45 sec

=> distance = D + 200

Time = 45 sec

Speed = 48 x5/18 = 40/3 m/s

=> D + 200/(40/3) = 45

=> D = 600 - 200 = 400 mts

Hence, the length of the bridge = 400 mts.

Let C.P. of each Magazine be Rs. 1

C.P. of P articles = Rs. P. 

S.P. of P articles = Rs. 40.

Profit = Rs. (40 - P)

Now, Gain% = ProfitC.P×100 = 40-PP×100 

Here 40-PP×100= 25

-->P = 32.