Which numbers are all prime
2, 4, 6, 8, 10
2, 3, 5, 7, 11
1, 3, 5, 7, 9
5, 10, 15, 20, 25

2, 3, 5, 7, 11

Step-by-step explanation:

Prime numbers only have 2 factors: 1 and themselves

What's wrong with the other number sets?

2, 4, 6, 8, 10

The only number in this set that is prime is 2.

1, 3, 5, 7, 9

The number 1 is neither prime or composite and 9 is composite.

5, 10, 15, 20, 25

All of these numbers are composite except for 5.

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2