It would be 3.25 cups
Since there is 2.5 cups for 10 servings then 0.25 per serving multiply that by 13 servings and you get 3.25.So it would be 3.25 cups for 13 servings
The quantity 5 more than a number t is labeled as (5+t)
Product of 9 and the quantity is labeled as = 9(5+t) which equals 45+9t
Result is less than 6 so the equation becomes
45+9t < 6

Positive square root of 0.25 = 0.5
Hope this helps. - M
-5 because a negative plus a negative is a positive this is why it is the right answer