If 40% of graphic novels were purchased by readers 30 years of age or older and 15 were chosen at random, what is the probability that at least 10 of them are 30 years or older?

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3

my answer is$ 12

step-by-step explanation:

because 15 -2=12

-7/8

step-by-step explanation:

instead of subtracting you add the -6/8 and -1/8