Question 35002
G=9D B=2D AND D=D G+B+D=144 THEN 9D+2D+D=144 OR 12D=144 THEN D=144/12 OR D=12

DANIEL HAS 12 STAMPS, GEORGE HAS 9*12 OR 108 STAMPS AND BRYAN HAS 2*12 OR 24 

STAMPS THUS THE TOTAL STAMPS IS 12+108+24 OR 144 STAMPS.