Question

Twenty stamps cost $8.40. How much does it cost to buy 5 stamps?

Answer 1

divide the 8.40 by 20. which is 0.42. then multiply by 5 which is $2.10

Answer 2

20 / 4 = 5
so divide 8.40 by 4 and you'll get your answer

Answer 3

or you can take the long route Link proposed you with.

Answer 4

thxs

Answer 5

or set up a proportion..
20/8.40 = 5/x (20 stamps to 8.40 = 5 stamps to x)
cross multiply
20x = (8.40)(5)
just finish the rest and solve for x and that will be your answer