How can you tell the age of your friend

1.Ask his or her to right his age :- say 16
2.then double it making 32
3. add 1 to it , making  33
4.Multiply it by 5 making 165
5.now at 5 to eat making 170
6.Now multiply it by 10 making 1700
7.then subtract 100 making it 1600
8.now ask him to tell the number.
9. you delete the last two digits the remaining number will be his or her age that is 16.

Time you would take to count one billion

If a Person counted at the rate of hundred numbers a minute and kept on counting for 8 hours a day, 5 days a week, it would take a over 4 weeks to count to 1 million and just over 80 years to reach 1 billion

A Wonder sum that is always the same

1.Take any three digit number in which the first digit is larger than the last
say 912.
2.reverse it making 219
3.And subtract the smaller from the larger , making 693
4.now add the result to the same number reversed that is 396.
The answer is 1089 and
will be 1089 whatever number you start with