Pierre, Flynn and Cyrus collected stamps in the ratio of 11 : 4 : 6. After Cyrus gave ¹₅ to Pierre and Flynn, Cyrus had 330 less stamps than Pierre. The number of stamps that Flynn had increased by 20%. How many stamps did Pierre and Cyrus have in the end?

	Pierre	Flynn	Cyrus
Before	11 u	4 u	6 u
Change	+ 0.4 u	+ 0.8 u	- 1.2 u
After	11.4 u	4.8 u	4.8 u

Number of stamps that Cyrus gave to Pierre and Flynn
= ¹₅ x 6 u
= 1.2 u

Number of stamps that Flynn received from Cyrus
= ²⁰₁₀₀ x 4 u
= 0.8 u

Number of stamps that Pierre received from Cyrus
= 1.2 u - 0.8 u
= 0.4 u

Number of less stamps that Cyrus had less than Pierre
= 11.4 u - 4.8 u 
= 6.6 u

6.6 u = 330

1 u = 330 ÷ 6.6 = 50

Number of stamps that Pierre and Cyrus had
= 11.4 u + 4.8 u
= 16.2 u
= 16.2 x 50
= 810

Answer(s): 810