#281 - Marbles Puzzle
There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.
How many marbles are in the box ?
There are 3 marbles (1 blue, 1 green, and 1 red).
#282 - Maths Classic Race Puzzle
Lavesh, Bolt, and Lewis race each other in a 100 meters race. All of them run at a constant speed throughout the race.
Lavesh beats Bolt by 20 meters.
Bolt beats Lewis by 20 meters.
How many meters does Lavesh beat Lewis by ?
Lavesh beats Lewis by 36 meters.
It is tempting to guess that Lavesh beats Lewis by 40 meters, but when Lavesh finishes and is 20 meters ahead of Bolt, Bolt is NOT 20 meters ahead of Lewis (he's only 16 meters ahead), and it will take a couple more seconds before Bolt increases his lead over Lewis to 20 meters.
To figure out the answer, we let Lavesh's speed be A meter/second. So it takes him 100/A seconds to finish the race. At this point, we know that Bolt has run 80 meters (since Lavesh beats him by 20 meters). So Bolt runs 80 meters in 100/A seconds, meaning that he is running at a speed of (80/(100/A)) meters/second, or (8A/10) meters per second.
So we then know that it takes Bolt 100/(8A/10) seconds to finish the race, or 125/A seconds. At this point, we know that Lewis has run 80 meters (since Bolt beats him by 20 meters). So Lewis runs 80 meters in 125/A seconds, meaning that he is running at a speed of (80/(125/A)) meters/second, or 80A/125 meters per second.
Now that we know Lewis's speed, we just need to figure out how far he had run when Lavesh finished the race. Since Lavesh finished in 100/A seconds, we can determine that Lewis had run (100/A) * (80A/125) = 8000/125 = 64 meters when Lavesh finished the race. And so Lavesh beat him by (100 - 64) = 36 meters.
#283 - Tricky Password Teaser
There was some system error in a mailing website because of which passwords of some clients got changed.
Here is a conversation between a client and mailing-website executive person.
Client : My password is altered.
Client : I am not able to logged-in.
Executive : The password is distinct this time and it got eight letters , out of which two are same of your previous password.
Client: thanks , now i am able to logged-in.
Whats the client old and new passwords ?
Old password : distinct , New Password : altered :p
#284 - Logic Problem
There is a bag which have 21 blue balls and 23 red balls. You also have 22 red balls outside the bag.
Randomly remove two balls from the bag.
* If they are of different colors, put the blue one back in the bag.
* If they are the same color, take them out and put a red marble back in the bag.
Repeat this until only one marble remains in the bag.
What is the color of the sole marble left in the bag ?
The last marble will be blue.
Since balls can only be taken out in pairs and you started off with an odd number of blues there is always going to be one blue left over that you'll keep putting back in the box until it's left on it's own.
#285 - Logical Puzzle Asked In Interview
I organized a small get together at my home.
In the party , i have a barrel with some whiskey in it.
Suddenly Guest 1 say 'I bet this barrel of whiskey is more than half full'.
'No, its less than half full' Guest 2 replied.
I don't have any measuring instrument and without removing whiskey from it , how can i determine which of the guest is right ?
Tilt the barrel until the whiskey barely touches the lip of the barrel. If the bottom of the barrel is visible then it is less than half full.If the barrel bottom is still completely covered by the whiskey, then it is more than half full.
#286 - Solve This Math Problem
3 kids Prinka Tanu and Vidushi got some chocolates.
Prinka gave Tanu and Vidushi as many chocolates as they already had.
Then Tanu gave Prinka and Vidushi as many chocolates as they already had.
Finally, Vidushi gave Tanu and Prinka as many chocolates as they already had.
Now each of them has 24 chocolates.
How many chocolates they had originally?
Prinka had 39 , tanu had 21 and vidushi had 12 chocolates initially.
Solve the problem in reverse way as below :
Prinka Tanu Vidushi
24 24 24
12 12 48
6 42 24
39 21 12
#287 - Labor Day Maths Puzzle
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
#288 - What Word Am I Looking For
I am looking for a word that change both gender and number when i add the letter 'S'.
What Word Am I Looking For ?
Princes (male and plural) add an 's' Princess (female and singular)
#290 - Trick Maths Riddle
I have a role of cloth 1km long.
I have a machine which cuts this role into pieces of 10 meter long cloth.
How long would it take for the machine to cut the roll if each cut took 4 secs ?
396 seconds
1000m would only take 99 cuts not 100.
so 4*99 => 396