₦airaland Forum

Obinoscopy:
The 73rd person. It's complex

cremedelacreme:
All the odd numbers will be survivors and all the even numbers killed. That is 1,3,5,7,....99 will survive while 2,4,6,8....100 will all die.

jaelz:
Please gimme answers to this with logical backings and proof to answer.

jaelz:
Please gimme answers to this with logical backings and proof to answer.

Remimadrid:
No 1 is the last person standing, why? he killed 2 and pass the sword to 3, 3 kill 4 and so on. Then it comes back to the beginning and 1 kills 3, till he is the last person standing

Remimadrid:
No 1 is the last person standing, why? he killed 2 and pass the sword to 3, 3 kill 4 and so on. Then it comes back to the beginning and 1 kills 3, till he is the last person standing

TessaJ:
LOL......laf wan tear my stomach ooo

Enouwem:
73 is the answer!

How?

Consider a case when there 2^numbers in circle. Each time the number reduces by half and finally at the last number 1 will remain.
example – 2^2 = 4
round 1 – 2 and 4 will be killed.
round 2 – 3 will be killed. One Remains

So our aim here should be to reach to a figure when 2^n number will come and person who will be holding the sword at that moment will survive.

when there are 100 people – closet 2^number will be 64.
so here our target it to find the person who is holding the sword when 64 people are remaining.

64 people remaining means 36 people killed.
As every alternate person is being killed so double of 36 i.e 72. So 72 person was killed at that moment and the sword was passed to 73 from 71 after killing 72.

so the moment when 64 people were remaining, 73 was holding the sword,
so 73 will survive the killings!!!
.
.
.
.
.

OR,

Use the Circular Left Shift method

There are 100 people.
100 in binary is 1100100.
Circular left shift 1100100.
We get 1001001.
Convert it back to base 10.
73rd is the last man standing.


OR,

MATHAMATICAL WAY THAT EVERY NIGERIAN WILL UNDERSTAND

First 1,3,5,7,9,11,13,15,17;19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,93,95,97,99(got sword, passed to 1)

Then 1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,85,89,93,97(sword passed to again)

Then 1,9,17,25,33,41,49,57,65,73,81,89,97(sword passed to 9)

Then 9,25,41,57,73,89(sword passed to 9 again)

Then 9,41,73(sword passed to 9 again)

Then 9,73(73 got sword & killed 9)

Thus the answer is “73"


Oh! And for the programmers or coders.

PYTHON CODE

# find the survivor
n = 100
peeps = range(1, n+1)
idx = 0
while len(peeps) > 1:
    peeps.pop((idx + 1) % len(peeps))
    # Trivia: because of changing index and len(peeps),
    # the code below is not exactly equal to "idx = (idx + 1) % len(peeps)"
    idx = 0 if (idx >= len(peeps)-1) else (idx + 1)
    
print peeps[0]

Output: 73

cremedelacreme:
All the odd numbers will be survivors and all the even numbers killed. That is 1,3,5,7,....99 will survive while 2,4,6,8....100 will all die.

only one person survived

Enouwem:
73 is the answer!

How?

Consider a case when there 2^numbers in circle. Each time the number reduces by half and finally at the last number 1 will remain.
example – 2^2 = 4
round 1 – 2 and 4 will be killed.
round 2 – 3 will be killed. One Remains

So our aim here should be to reach to a figure when 2^n number will come and person who will be holding the sword at that moment will survive.

when there are 100 people – closet 2^number will be 64.
so here our target it to find the person who is holding the sword when 64 people are remaining.

64 people remaining means 36 people killed.
As every alternate person is being killed so double of 36 i.e 72. So 72 person was killed at that moment and the sword was passed to 73 from 71 after killing 72.

so the moment when 64 people were remaining, 73 was holding the sword,
so 73 will survive the killings!!!
.
.
.
.
.

OR,

Use the Circular Left Shift method

There are 100 people.
100 in binary is 1100100.
Circular left shift 1100100.
We get 1001001.
Convert it back to base 10.
73rd is the last man standing.


OR,

MATHAMATICAL WAY THAT EVERY NIGERIAN WILL UNDERSTAND

First 1,3,5,7,9,11,13,15,17;19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,93,95,97,99(got sword, passed to 1)

Then 1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,85,89,93,97(sword passed to again)

Then 1,9,17,25,33,41,49,57,65,73,81,89,97(sword passed to 9)

Then 9,25,41,57,73,89(sword passed to 9 again)

Then 9,41,73(sword passed to 9 again)

Then 9,73(73 got sword & killed 9)

Thus the answer is “73"


Oh! And for the programmers or coders.

PYTHON CODE

# find the survivor
n = 100
peeps = range(1, n+1)
idx = 0
while len(peeps) > 1:
    peeps.pop((idx + 1) % len(peeps))
    # Trivia: because of changing index and len(peeps),
    # the code below is not exactly equal to "idx = (idx + 1) % len(peeps)"
    idx = 0 if (idx >= len(peeps)-1) else (idx + 1)
    
print peeps[0]

Output: 73

cremedelacreme:
All the odd numbers will be survivors and all the even numbers killed. That is 1,3,5,7,....99 will survive while 2,4,6,8....100 will all die.

Oly23:
The 73rd person is the last man standing

Enouwem:
73 is the answer!

How?

Consider a case when there 2^numbers in circle. Each time the number reduces by half and finally at the last number 1 will remain.
example – 2^2 = 4
round 1 – 2 and 4 will be killed.
round 2 – 3 will be killed. One Remains

So our aim here should be to reach to a figure when 2^n number will come and person who will be holding the sword at that moment will survive.

when there are 100 people – closet 2^number will be 64.
so here our target it to find the person who is holding the sword when 64 people are remaining.

64 people remaining means 36 people killed.
As every alternate person is being killed so double of 36 i.e 72. So 72 person was killed at that moment and the sword was passed to 73 from 71 after killing 72.

so the moment when 64 people were remaining, 73 was holding the sword,
so 73 will survive the killings!!!
.
.
.
.
.

OR,

Use the Circular Left Shift method

There are 100 people.
100 in binary is 1100100.
Circular left shift 1100100.
We get 1001001.
Convert it back to base 10.
73rd is the last man standing.


OR,

MATHAMATICAL WAY THAT EVERY NIGERIAN WILL UNDERSTAND

First 1,3,5,7,9,11,13,15,17;19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,93,95,97,99(got sword, passed to 1)

Then 1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,85,89,93,97(sword passed to again)

Then 1,9,17,25,33,41,49,57,65,73,81,89,97(sword passed to 9)

Then 9,25,41,57,73,89(sword passed to 9 again)

Then 9,41,73(sword passed to 9 again)

Then 9,73(73 got sword & killed 9)

Thus the answer is “73"


Oh! And for the programmers or coders.

PYTHON CODE

# find the survivor
n = 100
peeps = range(1, n+1)
idx = 0
while len(peeps) > 1:
    peeps.pop((idx + 1) % len(peeps))
    # Trivia: because of changing index and len(peeps),
    # the code below is not exactly equal to "idx = (idx + 1) % len(peeps)"
    idx = 0 if (idx >= len(peeps)-1) else (idx + 1)
    
print peeps[0]

Output: 73

JAVASCRIPT

// populate the array for 100 people
var team = new Array();
for (var i = 1; i <= 100; i++) {
 team[i - 1] = i;
}

var current;
var next;

var j = 0.
while (team.length > 1) { // loop until only 1 exists
 current = team[j];
 team.push(team[j]); // move current to the end
 team.shift(); // remove from existing
 next = team[j];
 team.shift(); // delete next
 document.writeln("Number " + current + " kills number " + next + "<br />";
}
document.writeln("The last one is number " + team[0]);
//alert(team[0]);

Enouwem:
73 is the answer!

How?

Consider a case when there 2^numbers in circle. Each time the number reduces by half and finally at the last number 1 will remain.
example – 2^2 = 4
round 1 – 2 and 4 will be killed.
round 2 – 3 will be killed. One Remains

So our aim here should be to reach to a figure when 2^n number will come and person who will be holding the sword at that moment will survive.

when there are 100 people – closet 2^number will be 64.
so here our target it to find the person who is holding the sword when 64 people are remaining.

64 people remaining means 36 people killed.
As every alternate person is being killed so double of 36 i.e 72. So 72 person was killed at that moment and the sword was passed to 73 from 71 after killing 72.

so the moment when 64 people were remaining, 73 was holding the sword,
so 73 will survive the killings!!!
.
.
.
.
.

OR,

Use the Circular Left Shift method

There are 100 people.
100 in binary is 1100100.
Circular left shift 1100100.
We get 1001001.
Convert it back to base 10.
73rd is the last man standing.


OR,

MATHAMATICAL WAY THAT EVERY NIGERIAN WILL UNDERSTAND

First 1,3,5,7,9,11,13,15,17;19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,93,95,97,99(got sword, passed to 1)

Then 1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,85,89,93,97(sword passed to again)

Then 1,9,17,25,33,41,49,57,65,73,81,89,97(sword passed to 9)

Then 9,25,41,57,73,89(sword passed to 9 again)

Then 9,41,73(sword passed to 9 again)

Then 9,73(73 got sword & killed 9)

Thus the answer is “73"


Oh! And for the programmers or coders.

PYTHON CODE

# find the survivor
n = 100
peeps = range(1, n+1)
idx = 0
while len(peeps) > 1:
    peeps.pop((idx + 1) % len(peeps))
    # Trivia: because of changing index and len(peeps),
    # the code below is not exactly equal to "idx = (idx + 1) % len(peeps)"
    idx = 0 if (idx >= len(peeps)-1) else (idx + 1)
    
print peeps[0]

Output: 73

JAVASCRIPT

// populate the array for 100 people
var team = new Array();
for (var i = 1; i <= 100; i++) {
 team[i - 1] = i;
}

var current;
var next;

var j = 0.
while (team.length > 1) { // loop until only 1 exists
 current = team[j];
 team.push(team[j]); // move current to the end
 team.shift(); // remove from existing
 next = team[j];
 team.shift(); // delete next
 document.writeln("Number " + current + " kills number " + next + "<br />";
}
document.writeln("The last one is number " + team[0]);
//alert(team[0]);

Enouwem:
73 is the answer!

How?

Consider a case when there 2^numbers in circle. Each time the number reduces by half and finally at the last number 1 will remain.
example – 2^2 = 4
round 1 – 2 and 4 will be killed.
round 2 – 3 will be killed. One Remains

So our aim here should be to reach to a figure when 2^n number will come and person who will be holding the sword at that moment will survive.

when there are 100 people – closet 2^number will be 64.
so here our target it to find the person who is holding the sword when 64 people are remaining.

64 people remaining means 36 people killed.
As every alternate person is being killed so double of 36 i.e 72. So 72 person was killed at that moment and the sword was passed to 73 from 71 after killing 72.

so the moment when 64 people were remaining, 73 was holding the sword,
so 73 will survive the killings!!!
.
.
.
.
.

OR,

Use the Circular Left Shift method

There are 100 people.
100 in binary is 1100100.
Circular left shift 1100100.
We get 1001001.
Convert it back to base 10.
73rd is the last man standing.


OR,

MATHAMATICAL WAY THAT EVERY NIGERIAN WILL UNDERSTAND

First 1,3,5,7,9,11,13,15,17;19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,93,95,97,99(got sword, passed to 1)

Then 1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,85,89,93,97(sword passed to again)

Then 1,9,17,25,33,41,49,57,65,73,81,89,97(sword passed to 9)

Then 9,25,41,57,73,89(sword passed to 9 again)

Then 9,41,73(sword passed to 9 again)

Then 9,73(73 got sword & killed 9)

Thus the answer is “73"


Oh! And for the programmers or coders.

PYTHON CODE

# find the survivor
n = 100
peeps = range(1, n+1)
idx = 0
while len(peeps) > 1:
    peeps.pop((idx + 1) % len(peeps))
    # Trivia: because of changing index and len(peeps),
    # the code below is not exactly equal to "idx = (idx + 1) % len(peeps)"
    idx = 0 if (idx >= len(peeps)-1) else (idx + 1)
    
print peeps[0]

Output: 73

JAVASCRIPT

// populate the array for 100 people
var team = new Array();
for (var i = 1; i <= 100; i++) {
 team[i - 1] = i;
}

var current;
var next;

var j = 0.
while (team.length > 1) { // loop until only 1 exists
 current = team[j];
 team.push(team[j]); // move current to the end
 team.shift(); // remove from existing
 next = team[j];
 team.shift(); // delete next
 document.writeln("Number " + current + " kills number " + next + "<br />";
}
document.writeln("The last one is number " + team[0]);
//alert(team[0]);

Enouwem:
73 is the answer!

How?

Consider a case when there 2^numbers in circle. Each time the number reduces by half and finally at the last number 1 will remain.
example – 2^2 = 4
round 1 – 2 and 4 will be killed.
round 2 – 3 will be killed. One Remains

So our aim here should be to reach to a figure when 2^n number will come and person who will be holding the sword at that moment will survive.

when there are 100 people – closet 2^number will be 64.
so here our target it to find the person who is holding the sword when 64 people are remaining.

64 people remaining means 36 people killed.
As every alternate person is being killed so double of 36 i.e 72. So 72 person was killed at that moment and the sword was passed to 73 from 71 after killing 72.

so the moment when 64 people were remaining, 73 was holding the sword,
so 73 will survive the killings!!!
.
.
.
.
.

OR,

Use the Circular Left Shift method

There are 100 people.
100 in binary is 1100100.
Circular left shift 1100100.
We get 1001001.
Convert it back to base 10.
73rd is the last man standing.


OR,

MATHAMATICAL WAY THAT EVERY NIGERIAN WILL UNDERSTAND

First 1,3,5,7,9,11,13,15,17;19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,93,95,97,99(got sword, passed to 1)

Then 1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,85,89,93,97(sword passed to again)

Then 1,9,17,25,33,41,49,57,65,73,81,89,97(sword passed to 9)

Then 9,25,41,57,73,89(sword passed to 9 again)

Then 9,41,73(sword passed to 9 again)

Then 9,73(73 got sword & killed 9)

Thus the answer is “73"


Oh! And for the programmers or coders.

PYTHON CODE

# find the survivor
n = 100
peeps = range(1, n+1)
idx = 0
while len(peeps) > 1:
    peeps.pop((idx + 1) % len(peeps))
    # Trivia: because of changing index and len(peeps),
    # the code below is not exactly equal to "idx = (idx + 1) % len(peeps)"
    idx = 0 if (idx >= len(peeps)-1) else (idx + 1)
    
print peeps[0]

Output: 73

JAVASCRIPT

// populate the array for 100 people
var team = new Array();
for (var i = 1; i <= 100; i++) {
 team[i - 1] = i;
}

var current;
var next;

var j = 0.
while (team.length > 1) { // loop until only 1 exists
 current = team[j];
 team.push(team[j]); // move current to the end
 team.shift(); // remove from existing
 next = team[j];
 team.shift(); // delete next
 document.writeln("Number " + current + " kills number " + next + "<br />";
}
document.writeln("The last one is number " + team[0]);
//alert(team[0]);