The answer is E. 9. Think of the worst case scenario - you could select 8 boxes with only 2 of each color. The next scarf has to give you three of one color.
First, we multiply 2x - 5y = 8 by (-2) and add it on to 4x + ky = 17
4x + ky = 17
-4x+10y = -16
10y + ky = 1
Then we factor out the y-
(10 + k)y = 1
To get a system with no solution, we need to make y equal 0. To do this, (10 + k) must equal 0. The answer is A. -10.
I. Only 7/25 people missed the target on the first throw, so this statement is true.
II. You can validate this statement by plugging the numbers into an equation to get the number of "true" hits to compare to the 25 misses. The equation I used for each group:
(number of people who missed on that throw)(throw number-1) = number of hits for that throw number. Then you add all the numbers together like so:
(7)(0) + (6)(1) + (6)(2) + (4)(3) + (2)(4)
You get 38 hits, which is greater than the 25 misses.
III. This statement is true because the table only goes up to 5 throws and if you add (7 + 6 + 6 + 4 + 2) you get 25.
The answer is E. I, II, and III.
Please let me know if you need any clarification