math
posted by miki on .
A box of pens contains 54 pens with black ink 36 with blue ink and 30 with red ink if you took 20 pens from the box how many would you expect to have blue ink black ink red ink?

the ratios of
black : blue : red = 54:36:30 = 9:6:5
let the number black be 9x
let the number of blues be 6x
let the number of reds be 5x
9x + 6x + 5x = 20
20x = 20
x = 1
so 9 black, 6 blue, and 5 red