Adam has some paint. He uses 5/8 of it to paint 4 chairs and 3 doors. The amount of paint needed to paint a door is 2 times that of a chair

(a) How many chairs can he paint using the remaining paint?
(b) How many doors can he paint using the remaining paint?

Let assume

Amount needed to paint chair = x
Amount needed to paint door = 2x

4x + 3(2x) = 5/8

10x = 5/8

x = 8 * 2
x = 1/16, 2x = 1/8
Remaining paint = 1 - 5/8 = 3/8
No. of chairs * 1/16 = 3/8

(a) No. of chairs = 48/8 => 6
(b) No. of doors * 1/8 = 3/8 = 3

(a) answer = 6, (b) answer = 3