Two Twins Eddy and Roberto Baggio were standing back to back and suddenly they started running in opposite direction for 4 kilometers and then turn to left and run for another 3 kilometers.
what is the distance between the Baggio twins when they stop ?
10 kilometers
Michael Phelps , the famous swimmer can swim downstream in a lake in exact 40 minutes (with the lake current helping time).
He can swim upstream in a lake in exact 60 minutes (against the lake current).
The length of lake is 2 kilometers.
How long Michael Phelps can cover distance of one side at a still lake (no current).
48 minutes
I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.
How Long will it take to fill the bucket?
3 hours
Explanation :
(1/6 + 1/4 - 1/12) ^ (-1)
= (1/3)^(-1) = 3
Manish drive to his office at 20km/hr. After reaching office, he realize that today is a holiday of 'Labor Day'.He went back at average speed of 30km/hr. Discounting the time spent in the stoppage what was his average speed of his journey ?
24km/hr (not 25km/hr which might be guessed by many)
D : distance traveled
T1 : time of going to office
T2 : time of returning back
Y : Average Speed
D = 20 * T1
T1 = D/20
D = 30 * T2
T2 = D/30
2D = Y(T2 + T1)
2D = Y(D/20 + D/30)
2D = Y(3D/60 + 2D/60)
2D = Y(5D/60)
Y = 120D/5D
=> Y = 24
I have two sand hour glasses:
1. A 7 minute one and
2. An 11 minute one.
Using just these 2 sand hour glasses, how can i measure time as 15 minutes ?
1. Start both the 7 minute hour glass & 11 minute hour glass.
2. Wait till the 7 minute hour glass times out. Time is 7 minute!
3. Restart the 7 minute hour glass. At this time 11 minute hour glass will have 4 minutes left to time out.
4. As soon as 11 minute glass times out invert the 7 minute hour glass. Total time now is 11 minutes.
5. After inverting 7 minute hour glass, it will now have 4 minutes left for time out.
6. After these 4 minutes times out, the total time is 15 minutes.
A large water tank has two inlet pipes (a large one and a small one) and one outlet pipe. It takes 3 hours to fill the tank with the large inlet pipe. On the other hand, it takes 6 hours to fill the tank with the small inlet pipe. The outlet pipe allows the full tank to be emptied in 9 hours.
What fraction of the tank (initially empty) will be filled in 0.64 hours if all three pipes are in operation? Give your answer to two decimal places (e.g., 0.25, 0.5, or 0.75).
In one hour,
Soln 1:
the large inlet pipe fills 1 / 3 of the tank;
the small inlet pipe fills 1 / 6 of the tank;
the outlet pipe empties 1 / 9 of the tank; and therefore
all three pipes together fill [ (1 / 3) + (1 / 6) − (1 / 9) ] of the tank.
Fraction of the tank that will be filled in 0.64 hours =
0.64 [ (1 / 3) + (1 / 6) − (1 / 9) ] = 0.25.
Soln 2:
Let V be the total volume of the tank. From equation (1),
Flow Rate (large inlet pipe) = V / 3
Flow Rate (small inlet pipe) = V / 6
Flow Rate (outlet pipe) = V / 9.
Substituting in equation (2),
Rate of Accumulation in tank = (V / 3) + (V / 6) − (V / 9).
Using the above result in equation (1),
Time required to fill the complete tank = V / [ (V / 3) + (V / 6) − (V / 9) ].
Note that V cancels out on simplifying the above expression.
Fraction of the tank that will be filled in 0.64 hours =
0.64 [ (1 / 3) + (1 / 6) − (1 / 9) ] = 0.25.
Two towns are exactly 100 km apart. Rakesh leaves City A driving at 30 km/hr and Harish leaves City B a half an hour later driving 60 km/hr. Who will be closer to City A when they meet?
Both would be the same distance from City A.
What Time Should the last watch show ?
5:19 Starting with the watch on the left, add 42 minutes to the time shown to give the time on the next watch to the right
Four people need to cross a dark river at night.They have only one torch and the river is too risky to cross without the tourch. if all people cross simultanoesly then torch light wont be sufficient.Speed of each person of crossing the river is different.cross time for each person is 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the river ?
The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.
Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins
Distances from you to certain cities are written below.
BERLIN 200 miles
PARIS 300 miles
ROME 400 milesAMSTERDAM 300 miles
CARDIFF ??? miles
How far should it be to Cardiff ?
100 miles. Each vowel is worth 300 and each consonant is worth -100. These are totalled in each city name to give the distance