solve r to the nearest 10th of a centimetre

The ratio of blue cards to green cards is 2 to 5. there are 8 blue cards. complete the diagram and explain how you can find the number of green cards.

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?