IQ QUESTIONS

as most of you know, i love IQ questions although i never get to answer it . always. 

so , Carynn asked me some IQ question that i think is pretty interesting. here it is :

1) there are 8 marbles. 7 with the same weight and one heavier than the rest. one weighing machine like the one below have been given to you and you can just use it twice at most. So how do you know which is the heavier marble?

2) 8 buckets are provided. each bucket has 100 marbles in it. all the marbles in 7 buckets are weight 1.0g. the last bucket left has marbles that are 1.1g. you are given an empty bucket ( it is up to you whether do you want to use it) and a digital weighing machine ( you can only use it ONCE). Which bucket has the marble which weight is 1.1g?

3) One 3litres bucket and one 5 litres bucket is provided. How can you measure 4 litres of water? ( bucket doesnt have measurements )

4) one mosquito coil takes an hour to burn. how do you know it has already burnt for 30 minutes? ( just to let you know, answer has nothing to do with cutting the coil into half and measuring the coil ) ;)

if you get that right, continuous question is

5) now you are given 2 coils . how do you know it has already burnt for 45 minutes?

ANSWERS:

will be given next post ;)