There are infinitely many groups. Some examples are given below.
Additive:
(1, 1, 1, 3)
(1.1, 1.1, 1.1, 2.7)
(-1, 1, 1, 4) etc
Multiplicative:
(1, 1, 1, 6)
(2, 2, 2, 0.75)
(3, 3, 3, 6/27) etc
You could, of course, have Irrational Numbers.
numbers are less than or equal to 10: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and all the negative numbers
4 and 2/10 + 3 and 3/10
the two numbers are 14 and - 4.
Not counting negative numbers (which would give you an infinite number of ways of adding numbers together to equal 10), there are 6 different ways (permutations) of adding numbers together to equal 10. 0 + 10 1 + 9 2 + 8 3 + 7 4 + 6 5 + 5
Of the numbers in that list, the perfect squares are 4 (equal to ±22), 9 (equal to ±32), 16 (equal to ±42) and 25 (equal to ±52).
they can be 2 groups of 16, 4 groups of 8, 8 groups of 4, or 16 groups of 2
-66
numbers are less than or equal to 10: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and all the negative numbers
3 + 4 + 5 - 2 = 10
5,5, and 4
4 and 2/10 + 3 and 3/10
the two numbers are 14 and - 4.
2 and 10 or 4 and 5
There are five ways to do this, if you include 32 'groups' with one member each.The others are 2 groups of 16, 4 groups of 8, 8 groups of 4 and 16 groups of 2.
14
Not counting negative numbers (which would give you an infinite number of ways of adding numbers together to equal 10), there are 6 different ways (permutations) of adding numbers together to equal 10. 0 + 10 1 + 9 2 + 8 3 + 7 4 + 6 5 + 5
She can have 1 group of 40, 2 groups 0f 20, 4 groups of 10, 8 groups of 5, 5 groups of 8 10 groups of 4, 20 groups of 2 or 40 groups of 1. This assumes that you don't want any partial books in any of your groups.