I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

What can you hold in your right hand, but never in your left hand?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

What has 13 hearts but no other organs?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

What does man love more than life, hate more than death or mortal strife; That which contented men desire; the poor have, the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?