During summer, when the snow melts, the water level of the Yukon River increases. If the water level of the river increased by 72 centimeters in 8 days, what is the water level increase rate in centimeters per day?

A. 9 centimeters per day
B. 12 centimeters per day
C. 11 centimeters per day
D. 8 centimeters per day

A) 9cm/day

Step-by-step explanation:

72/8=9

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

answer: bearing in mind that a rectangle has a perimeter of length + length + width + width.

step-by-step explanation:

p = perimeter

l = length

x=width

p = 2l + 2x

p = 2(l+x)     < ==== perimeter of the base of the box.