1.i know a way by which i can make i can get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
do you ?

2.the puzzle: here is a famous prize problem that sam loyd issued in 1882, offering $1000 as a prize for the best answer showing how to arrange the seven figures and the eight 'dots' .4.5.6.7.8.9.0. which would add up to 82

3.at a party, everyone shook hands with everybody else. there were 66 handshakes. how many people were at the party?

4.can you find a seven digit number which describes itself. the first digit is the number of zeros in the number. the second digit is the number of ones in the number, etc. for example, in the number 21200, there are 2 zeros, 1 one, 2 twos, 0 threes and 0 fours.

5.
2+3=8,
3+7=27,
4+5=32,
5+8=60,
6+7=72,
7+8=? ?

6.can you arrange four 9's and use of atmost 2 math symbols , make the total be 100?

7.you can place weights on both side of weighing balance and you need to measure all weights between 1 and 1000. for example if you have weights 1 and 3,now you can measure 1,3 and 4 like earlier case, and also you can measure 2,by placing 3 on one side and 1 on the side which contain the substance to be weighed. so question again is how many minimum weights and of what denominations you need to measure all weights from 1kg to 1000kg.