Possible values are
x=1,y=11
x=2,y=8
x=3,y=5
x=4,y=2
We can't see the whole question :/
If the smaller number is x, then the larger number has to be 20 - x in order for the arithmetic mean to be 10, as their sum must be 20.
If the geometric mean is 8 the product of the numbers has to be 64 and so the larger number is 64/x
Solving 64/x = 20 - x gives the quadratic x^2 -20x +64 = 0 so x = 4 or 16.
The two numbers are 4 and 16.
There are 7 math books, 9 science books and 5 literature books. Student has to select 2 books from each set.
This is a combination problem.
Number of ways to select 2 math books from 7 books = 7C2 = 21
Number of ways to select 2 science books from 9 books = 9C2 = 36
Number of ways to select 2 literature books from 5 books = 5C2 = 10
Total number of ways to select 2 books from each set = 21 x 36 x 10 = 7560 ways.
So there are 7560 ways to select 2 books from each set of seven math books, nine science books, and five literature books
