The formula for density = number/ area
In this case number=20
area = 5m^2
Density = 20/5=4 mice per m^2
The right answer is <span>A. 4 per m2</span>
Whole numbers are like 0,1,2,3,4,5...
the smallest one is 10
prime numbers
I do not accept 1 as a prime number, if you agree, go to AAAAAAAAA
if you do think it's a prime number, go to BBBBBBB
AAAAAAA
2,3,5,7
2+3+5+7=17
a+b=10+17=27
BBBBBBBBBBB
1,2,3,5,7
1+2+3+5+7=18
a+b=10+18=28
if you do not think a is a prime number, then the answer is 27
if you do think 1 is prime number then the answer is 28
first：76 ÷ 19/25=100
a:80 / 20 * 1 / 25 =0.16
b:80 * 5/4 =100
c:80 / 5 ÷ 1 / 4 =64
d:80 * 5/4 =100
e:80 * 4/5 =64
So I think both B and D should be the right answer
