Since it is already stated that 52% of the 450 stamps are red (which is 234), the remaining 216 stamps are composed of blue and green stamps only. From there, we can write the equation:
216 = b + g
where: b = blue stamps; g = green stamps
Applying the relation that the green stamps are 3/5 as much as the blue stamps, we can say that g = 3/5 b
Substituting the relation to the equation:
216 = b + 3/5 b
216 = 8/5 b
Dividing both sides by 8/5:
216/ (8/5) = 8/5 b / (8/5)
b = 135.
Going back to the equation and substituting the value of b:
216 = b + g
216 = 135 + g
Subtracting 135 from both sides to get g:
216 - 135 = 135 - 135 + g
g = 81
Therefore, there are 135 blue stamps and 81 green stamps.
