Answer:
12.5
Step-by-step explanation:
4+21=25
25/2=12.5
This is Pythagorean's Theorem, with one leg being 10 and the hypotenuse being 16. Using those values in the theorem looks like this:

and

and

so

Take the square root of both sides to find that b = 12.5
Answer:
The answer is D - Two
Step-by-step explanation:
a chord has two endpoints on a circle
If we know that Pedro bought 1

pounds of red sand, and 5

pounds of brown sand, and they both cost $4.60, then we just have to add the individual amounts of sand, since they cost the same.

So Pedro bought

lbs of sand overall. Now, we just need to multiply the cost per pound by the total amount of sand he bought.

Pedro spent $31.05 on sand, which is answer choice B.
Hope that helped =)