MATH
posted by kIM .
A manufacturer produces three types of radios: deluxe, standard and economy. Each radio uses three different types of transistors: P, Q and R. The deluxe radio uses 2 P's, 7 Q's and 1 R. The standard contains 2 P's, 3 Q's and 1 R, and the economy model requires 1 P, 2 Q's and 2 R's.
How many radios of each type can be constructed if the total number of transistors (P's, Q's and R's) available are 2200, 3400 and 1400 respectively and all transistors must be used?

the same question came up a few days ago, were you the same person?
http://www.jiskha.com/display.cgi?id=1310104839 
No she is my friend, she refered me to this website. we are taking the same course.
I am stuck with this question, and I don't know how to solve it. Im getting x as 5 for some reason :S 
Please helpp!!!!