GATE Questions

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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.

Let the present ages be K,M

Given K/M = 4/5

5K - 4M = 0 ......(1)

Also given that,

M - (K + 5) = 3

M - K = 8 .........(2)

Then, by solving (1) & (2)

M = 40 yrs and K = 32 yrs

Hence, Total of ages = 40 + 32 = 72 yrs

Difference of ages = 40 - 32 = 8 yrs.

Speed of train relative to man = 67 - 7 = 60 km/hr.
= 60 x 5/18 = 50/3 m/sec.

Time taken to pass the man = 600 x 3/50 = 36 sec.

World Suicide Prevention Day (WSPD) is an awareness day celebrated on 10 September every year, keeping in mind the end goal to give overall commitment and action to anticipate suicides, with various activities around the world since 2003.

Let the speed of the boat in still water is 'w'

Speed of the current is 'c'

Let the distance between two places is 'd'

According to the question, motorboat takes half time to cover a certain distance downstream than upstream.

dw+c = 12dw-c

=> 2w - 2c = w + c

=> w = 3c

=> c : w = 1 : 3

Hence, the ratio between rate of current(c) and rate of boat in still water(w) = 1 : 3

According to the given data,

Let Cost price of the article be 'cp'

Then,

102.25 cp - 92 cp = 164 x 100

10.25 cp = 16400

cp = 1600

Now, if he sells at Rs. 1760

Profit = 1760 - 1600 = 160

Profit% = 160/1600 x 100 = 10%.