The man said, "My head will be chopped off."

Nine days.

Fill up the 3 gallon container first. Pour it into the five gallon container. Fill up the 3 gallon container again, and fill up the rest of the 5 gallon container, and you should have 1 gallon left over in the 3 gallon container.

1.5

4 crayons.

Bulldoze.

Jungle bells! Jungle bells!

One girl took the basket. She took the last apple while it was in the basket.

Because he's always 'spotted'.

A strawberry.

We first look with which numbers each number can form a pair of which the sum is a square:

Number:
Number 1 Square pairs: 1+3
1+8
1+15
Number 2 Square pairs: 2+7
2+14
Number 3 Square pairs: 3+1
3+6
3+13
Number 4 Square pairs: 4+5
4+12
Number 5 Square pairs:
5+4
5+11
Number 6 Square pairs:: 6+3
6+10
Number 7 Square pairs: 7+2
7+9
Number 8 Square pairs: 8+1 Number 9 Square pairs: 9+7
9+16
Number 10 Square pairs: 10+6
10+15
Number 11 Square pairs: 11+5
11+14
Number 12 Square pairs:12+4
12+13
Number 13 Square pairs:13+3
13+12
Number 14 Square pairs:14+2
14+11
Number 15 Square pairs:15+1
15+10
Number 16 Square pairs:16+9
As can be seen, there are two numbers that can form a pair in only one way: 8 and 16. Therefore, these two numbers need to be at the start or at the end of the sequence. If we start with the number 16, the sequence follows almost automatically: 16 9 7 2 14 11 5 4 12 13 3 6 10 15 1 8. Of course, the reverse sequence is also a possible solution.

HIRX

The first three letters move four places forward in the alphabet, while the fourth letter moves forward five places