Play with expressions

Using numbers 1, 2, 3, 4, 5, 6 once and only once, can you get 791?
Operations allowed are - addition [+], subtraction [-], multiplication [*], division [/] and Exponentiation [^] . Parentheses [()] can be used.

Fill the blanks

Write 1 to 9 digit in these blanks.... and make this expression = 100
Needless to say BODMAS applies

_ / _ *_ + _ * _ *_ / _ + _ * _

Missing £1

Three people check into a hotel. They pay £30 to the manager and go to their room. The manager suddenly remembers that the room rate is £25 and gives £5 to the bellboy to return to the people. On the way to the room the bellboy reasons that £5 would be difficult to share among three people so he pockets £2 and gives £1 to each person. Now each person paid £10 and got back £1. So they paid £9 each, totalling £27. The bellboy has £2, totalling £29. Where is the missing £1?

Hacky-Sacks

Recently at an expo where Residex had a stall, our budding sales rep Jono Winfield went there to give away promotional Residex hacky-sacks.
Being an orderly sort of person (Army background), he attempted stacking them in piles of three each. However, much to his chagrin (and annoyance), he had one left over.
So he tried stacking them in piles of 5. Again, one left over.
He tried twice more, this time in piles of 7 and piles of 9. Again, however, there was one elusive Residex hacky-sack left over.
Finally, he tried one last time in piles of 11. This time, the piles worked out beautifully.
What was the minimum number of hacky-sacks that Jono would have had?