takes her 20 minutes to walk 1/2 a mile
2 miles=80 minutes
1/4= 10 minutes i think
so 80+10=1 1/2
{This is not my work!!!}
38 yard piece for each student and there are 16 students:
38*16=608
608 yards needed for your class
Hey there mate!
Please check the attached answer of picture for explanation.

Answer:
5.3
Step-by-step explanation:
You use the Pythagoras theorem which is a^2+b^2=c^2.
Since you're solving for a side length that's not the hypotenuse you will manipulate the equation to c^2-a^2=b^2. From here you just plug in numbers.
8^2 - 6^2 = b^2
64 - 36 = b^2
b = sqrt(28)
b = 5.2915.... = 5.3
Sqrt(15) would be irrational
Answer is B