How many of the given species having atleast having at least 25% s-character in the hybrid orbital of central atom?

CH₃^-,NH₂^-,I₃^-,XeF₂,XeO₃,XeO₄,XeO₂F₂,XeOF₄,

NCO^-

s-character is the commitment of sigma sort bond in a hybridization: sp3 = 25% s-character, 75% p-character sp2 = 33% s-character, 66% p-character sp = half s-character, half p-character The more s-character a bond has, the more grounded and shorter the bond is. so a sp-sp bond is most grounded, and sp3-sp3 bond is weakest. 

-     NH2 , XEF2 , XE02FE all have 25% s character