-2
2+2^2+2^3+2^4-2^5=-2
Let S be the set of all 5 digit numbers formed by the digits 1, 2, 3, 4, 5 without repetition. What is the sum of all numbers in S?
Use the digits 1, 2, 3, 4, 5 and 6 once only, in this multiplication sum to make it correct.
? ? x ? ——- ? ? ?
The digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 can be arranged into an addition sum to add up to almost any total, except that nobody has yet found a way to add up to 1984. However 9 digits can equal 1984 by an addition sum. Which digit is omitted?
