Weigh X and Y. And see which is the lightest.
take the lightest of X and Y and weigh it against A or B. See which is the lightest among them and weigh it against the remaining coin.
So the answer is 3 weighs.
We will use a weigh measurement machine.
Initially, it will show weight @ zero. Now start putting coin one-by-one and measure the weight every-time a coin is placed. Where the difference in unit weight is minimum, then that coin will be the lightest.
Eg. when coin 1 is placed- total weight = 30 gms
when coin 2 is placed- total weight = 40 gms (cumulatively)
when coin 3 is placed- total weight = 45 gms (cumulatively)
So the lightest coin is 3rd coin.
We can make pair of two. Then out of each pair, find out the lightest and then form two pairs. Again find the lightest coin in each pair and then form a pair of obtained coins. Lightest of these two is the one required. Total 7 steps. I think this is the answer.
as there are 8 coins..put 4 on one side and the other remaining 4 on the other side.. obviously one side will be lighter..
now the possible combinations of coins which can be on the lighter side are:
1)x,x,,x,a 2)x,x,x,b 3)x,x,x,y 4)x,x,y,y 5)3)x,x,y,a 4)x,x,y,b 5)x,x,a,b 6)x,y,a,b 7)x,y,y,a 8)x,y,y,b 9)x,y,y,y 10)y,y,y,a 11)y,y,y,b 12)y,y,a,b
well whatever the combination be, you need to divide it again into a group of 2-2..you will again get a lighter group..finally compare the last two coin and u will get the lightest coin of the 8 coins given...
so, that makes a total of 3 steps..
thumbs up..!! :)
# refer the above possibilities to get a clearer picture
A blindfolded man is asked to sit in the front of a carrom
board. The holes of the board are shut with lids in random
order, i.e. any number of all the four holes can be shut or
Now the man is supposed to touch any two holes at a time and
can do the following.
? Open the closed hole.
? Close the open hole.
? Let the hole be as it is.
After he has done it, the carrom board is rotated and again
brought to some position. The man is again not aware of what
are the holes which are open or closed.
How many minimum number of turns does the blindfolded man
require to either open all the holes or close all the holes?
Note that whenever all the holes are either open or close,
there will be an alarm so that the blindfolded man will know
that he has won.
A, B and C are three points on a straight line, not
necessarily equidistant with B being between A and C. Three
semicircles are drawn on the same side of the line with AB,
BC and AC as the diameters. BD is perpendicular to the line
ABC, and D lies on the semicircle AC.
If the funny shaped diagram between the three semicircles
has an area of 1000 square cms, find the length of BD.
Jim lies a lot. He tells the truth on only one day in a week.
One day he said: "I lie on Mondays and Tuesdays."
The next day he said: "Today is either Sunday, Saturday or
The next day he said: "I lie on Fridays and Wednesdays."
On which day of the week does Jim tell the truth?
SlowRun Express runs between Bangalore and Mumbai, For the
up as well as the down journey, the train leaves the
starting station at 10:00 PM everyday and reaches the
destination at 11:30 PM after three days.
Mr. Haani once travelled by SlowRun Express from Mumbai to
Bangalore. How many SlowRun Express did he cross during his
Annie, Bunnie, Candy and Dina visited Edy on 14th February.
1. The time of each visit was as follows:
- Annie at 8:00
- Bunnie at 9:00
- Candy at 10:00
- Dina at 11:00
Each time mentioned above may be either AM or PM.
2. Candy did not visit Edy between Bunnie and Dina.
3. At least one female visited Edy between Annie and Bunnie.
4. Annie did not visit Edy before both Candy and Dina.
Can you tell at what time did they individually visit Edy?
A farmer needs 8 gallons of water. He has only three unmared
buckets, two 6 gallon and one 11 gallon bucket.
How can he collect 8 gallons of water using three unmarked
buckets? Provide solution with minimal water wastage.
A cube painted on all six sides by red color is divided
into 125 equal cubes find
i) number of cubes having
a)3 faces colored
b)2 faces colored
c) 1 face colored
d)0 faces colored
ii)Find probability of picking a cube having red face