You buy two rolls of wrapping paper. Each roll has the same lateral surface area. What is the diameter of roll B? Roll A: height:3 length:30. Roll B: height:D Length:24

The area of lateral surface is equal that the perimeter multiply by the length. So the lateral surface area of roll A is 3*π*30=90π. Roll B: d*π*24=24dπ. Put them together: 90π=24dπ. So d=3.75 in.

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