28 Sec
– While the train is moving, the jogger will also be running in the same direction.
– for the head(engine) of the train to get to the current position of the jogger 240m away, it will take:
45km/hr => 12.5m/s => 240/12.5 = 19.2 seconds.
– But in the same period of time, the jogger will still be running and will have moved to a new location by: 9km/hr => 2.5m/s => 2.5 * 19.2 = 48m
To get to the new location at the speed of 12.5m/s will take the train:
48/12.5 = 3.84sec
In this additional time, the jogger will move forward by:
3.84 * 2.5 = 9.6m
at a speed of 12.5m/s, it will take the train less than a second to cover the additional 9.6m
If we add the distance the jogger will cover in 1 second to 9.6, it is still less than what the train can cover per second. let us see (9.6 + 2.5 = 12.1)
Therefore, the head of the train will pass the runner at approximately: 19.2 + 3.84 + 1 => 24.04 seconds.
For the train to completely pass the runner, it will need its whole length of 120m to be in front of the runner.
This will take an additional (9.6 + 2) seconds.
Therefore for the length of the train to be ahead of the runner it will take approx. 35.65 (24.04 + 9.6 + 2) seconds
9999991 (6k+_1) form
The formula to find number of diagonals (D) given total number of vertices or sides (N) is
N * (N – 3)
D = ———–
2
Using the formula, we get
1325 * 2 = N * (N – 3)
N2 – 3N – 2650 = 0
Solving the quadratic equation, we get N = 53 or -50
It is obvious that answer is 53 as number of vertices can not be negative.
Alternatively, you can derive the formula as triange has 0 diagonals, quadrangel has 2, pentagon has 5, hexagon has 9 and so on……
Hence the series is 0, 0, 0, 2, 5, 9, 14, …….. (as diagram with 1,2 or 3 vertices will have 0 diagonals).
Using the series one can arrive to the formula given above.
How will you know the odd is in lighter one or heavier one from only one weighing. It will require 2 weighing to find the odd set and one weighing for odd coin in that set i.e total 3 weighings.
300%
I am looking for a qualified chartered accountant in my profile who is known for his excellence in the field.
I have seen a few say 25% as an answer to this. But looks
like their math isn’t good and is extremeley complex to
have an asnwer of 25% to this question. Consider – Rs.1.00/-
per mango; so 40 mangoes = Rs.40.00/-, implies Rs.4.00/-
extra at the end of the deal. So he’s left with Rs.44.00/-
after selling 40 mangoes implies a profit of Rs.4.00/- over
Rs.40.00 = 44/40 = 110% which means his profit is 10%.
Hope this helps…
Thanks.
this is a simple question but the questionaire needs us to
consume time.
speed of car = 2 * speed of auto.
auto takes 30 mins then car should take only 15 mins.
total time = 10 mins + 15 mins = 25 mins = (a)
Son in law
45