Joshua bought a box if pens. 1 8 of the pens were black 1 4 were blue and 2 5 of the remaining were red. If there were 18 red pens, how many pens did she buy?

Answer 1

Let "x" be the total number of pens Joshua bought.
The number of black pens is 1/8*x
The number of blue pens is 1/4*x
The number of remaining pens is x - (1/8*x) - (1/4*x)
The number of red pens is 18 = (2/5)(x - (1/8*x) - (1/4*x))
18 = (2/5)(x - (1/8*x) - (1/4*x))
18 = (2/5)((13/8)*x)
18 = (26/40)*x
18(40/26) = x
28 = x
Joshua bought 28 pens. Answer: \boxed{28}.