L= 5100 -> N = 5100/ 3.4x2=3000 (nu) 
A+G=3000/2=1500 mà A=2/3G -> G=900 =X, A=600 =T 
%A=%T =600/3000x100=20% 
%G=%X =900/3000x100=50% - 20% = 30% 
H=2A+3G=2x600+3x900=3900 
chu kì:3000/20=150 
A1=200=T2 ->A2=T1=400 
X1=300=G2->G1=X2=600