Question

You have 8 objects of similar size, but one object weighs a little bit more than the others. Given a balance scale, you must find out which object it is, but you may only use the scale twice.

What do you do?

Answer 1

If you allow me thrice, then I have the answer

Answer 2

Great; they say it can actually be done with only 2 "weighing" steps but still, I wanna see your answer!

Answer 3

Just divide the 8 things into two groups, and place it in each of the pans of your balance.

Answer 4

*of course two equal groups of 4

Answer 5

So now you know when 4 contains the heavier one

Answer 6

Divide that group into 2 groups each of 2,

Answer 7

Now you know which two contains the heavier one

Answer 8

how about 3 and 3 for the first weighing?

Answer 9

Now again place them, and you know the culprit

Answer 10

@satellite
Great; what's the rest

Answer 11

then if they are equal it is one of the other two, one weighing does it

Answer 12

and if it is one of the groups of 3, then weight two out of the three: if they are equal then it is the third

Answer 13

satellite73 solved it

Answer 14

i think that does it

Answer 15

Very cool!

Answer 16

here is a question, that i can do but always have to start fresh because i always forget.
how do i multiply two 2 digit numbers with only 3 multiplications?
example
24
x 53

Answer 17

i am guessing adg knows because it is related to computer algorithms.

Answer 18

Now solve this:
There are 10 cigarette packets, each containing 10 cigarettes. One of the packets contain cigarettes which are a bit heavier than the cigarettes in any of the other packets. Although each cigarette in anyone packet weighs the same.
Now with just one weighing you need to find out the culprit box.

Answer 19

i have seen this one before so i keep quiet

Answer 20

great satellite73!

Answer 21

just select cigarettes from each box and compare!

Answer 22

You are allowed to weight only once

Answer 23

However, I must mention, you are allowed to use standardized weights

Answer 24

right

empty one box, leaving 1 cigarette in, and stuff that box with cigarettes from other boxes. and then..... I'm stuck :(

Answer 25

Oh! Just don't try it that way. Keep it with you for a few days, then come back. You will surely have solved it by then

Answer 26

lol

Answer 27

alright... just look at the boxes and compare the weights...

Answer 28

ok i remember now. you can multiply 53 times 24 with 3 multiplications instead of 4