Please give me the ans to this chem Q

Dear Student, The general formula for molecules having more than one double or triple bond keeps on changing. Alkanes have general formula CnH2n+2​. A single double would eliminate 2 hydrogens, hence the formula CnH2n​. If two double bonds are present then the formula would be CnH2n-2 as two more hydrogens are eliminated. Similarly a second triple bond would eliminate 4 more hydrogens and the formula would be CnH2n-6. For example: alkene - CH2=CH2 ; C2H4 (gen formula - CnH2n , where n=2) diene - CH2=CH-CH=CH2 ; C4H6 (gen formula - CnH2n-2 , where n=4) alkyne - CH≡CH ; C2H2 ​(gen formula - CnHn , where n=2)​ dialkyne - CH≡​C-C≡​CH ​(gen formula - CnH2n-6 , where n=4)​​. Regards